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AMERICAN 



HOROLOGICAL JOURNAL, 



DEVOTED TO 



PRACTICAL HOROLOGY. 



SMITH* 



"VOL. II. 



NEW YORKs 
Or. B. MILLE 
1871, 



Union Printing House, 79 John Street, N. Y. 



b« 



« , '^ : - 



CONTENTS OF VOL. II. 



ANSWERS : 

Catalogue of Stars 

Adjusting Transit 

Explanation of Chronometer Escapement 

Blan ^hing Silver 

Key Pipes 

Fitting Centre Pinions. 

Rose Drill 

Drilling Glass , 

Finding Length of Peudnlum 

Mr. Hermann 

Watch Repairing 

Reduction of Alloys 

Marion "Watch Factory 

Height of Work Bench 

Poised Levers 

Crimson Watch Hands 

Bronzing 

Watch Book 

Tenacitv of Metals 

Inspired Watch 

Swing Rest 

Coating Iron with Copper. 

Horologium 

Alchemy 

Diamonds 

Charging Magnetic Needle , 

Filling Engraving , 

Making Pendulum 

Regulating Watch with Breque^ Spring 

Effect of Work on the Eyes 

Inside Caliper ., 

Etruscan Jewelry 

Polishing 

Observations 

Brequet Hairspring 

Bad Work 

Amber 

Diamond Drills 

Finding Numbers for Lost Wheel 

Hardening Chronometer Springs 

Bond*s Chronograph 

Polishing Brass Work 

Straightening Arlxirs 

Solution for Cleaning Silver 

Prevention of Rust on Steel 

Time Ball 

Using Benzine instead of Alcohol 



ing Transit 

" to Temperature and Position . . . .105, 120, 152, 

Astronomical Terms 

it of Rate3 of Chronometer 

Amber 

Alloys of Gold 249, 

Brass 

Metals 

Alcherr.r 



'AGE 
46 
46 
46 

47 

47 

47 

47 

47 

48 

48 

68 

69 

71 

71 

94 

95 

95 

95 

96 

96 

119 

120 

120 

140 

141 

143 

143 

143 

144 

191 

192 

192 

215 

215 

215 

216 

238 

238 

238 

239 

239 

, 240 

, 283 

, 283 

. 283 

283 

284 

. 46 
58 
81 
180 
238 
271 
204 
is} 
140 



Ik (oik * B 

Blanching Silver 47 

Benzine 284,114 

Brass Alloy 204 

; Watch 236 

Bronzing Iron . 95 

Breqnet Hair-Spring .. 215 

Bid Work 2,16 

Bond's Chronograph 239 



CoilUKSPONDENCE : PAGE 

Horological Institute — J. H 4 

Electricity and Magnetism — E. S 12 

Calipers 192 

Chronometer Spring, to Harden 239 

' ' Escapement 6, 25, 46 

Chronograph 239 

Calculation of Wheel Teeth 19 

Coming Workmen 36 

Cleaning Watches 45 

Catalogue of Stars 46 

Centre Pinion 47 

Chronography 63 

Construction of a Perfect Watch 145, 193, 217, 241, 265 

Coating Iron with Copper 120 

Charging Magnetic Needle 143 

Crimson Watch-hands 95 

D 

Determining Distances 23 

Drill, Rose 47 

Drilling Glass 47 

Drills and Taps 115 

Deadbeat Escapement ' . . . . 119 

Diamonds 141, 213 

Diamond Drills 238 

Dialing. 21,40,55,87 

E 

Electro-Metallurgy 69 

Engraving . . 133 

to Fill 158, 143 

Eyes, Effect of Work Upon 191 

Etruscan Jewelry 192 

Enamels 252 

Escapement, Chronometer 6 

Electricity and Magnetism 12 

Escapement, Lever 83, 103 

F 

Flow of Metals 333 

Fork and Roller 366 

Files 109 

Fair of American Institute 116 

Fitting Centre Pinion 47 

Finding Length of Pendulums 48 

" Numbers of Lost Wheel 238 

G 

Grossman n's Pendulum, Analyzed 31 

Garlic Juice vs. Magnetism 93 

Good Time 212 

Gold Alloy 249, 271 

H 

Horological Journal, Announcement 13 

Herrmann 48 

Horologium 120 

Hair-Spring Gauge 134 

' ' Measurement 179 

" Brequet 215 

" to Harden 239 

Heat 34, 51, 78, 99, 121, 175, 201, 223 

Hole in Main Spring 135 

Hardening Steel 262 

Height of Work-Bench 71 



CONTENTS. 



Isochronal Adjustment 14 

Isochron ism 39 

Industrial Exposition at Altona 67 

Invention 97 

Inside Caliper 192 

Inspired Watch 96 



Jewelling 59 

Jean Paul Gamier 64 

K 

Key Pipes 47 



Latitude and Longitude into Time 23 

Light 135, 165, 188, 207 

Lever Escapement 83, 103 

«' Poised 94 

M 

Magnetism vs. Garlic Juice 93 

Metals, Tenacity of 96 

Magnetic Needle, to Charge 143 

Metals . . 160 

" Alloys of 184 

Monograms 264. 282 

Marion Watch Factor}' 71 

Making Pendulums 143 

o 

Opticians 163 

Observations 216 



Pendulum, Grossmann's Mercurial 1 

Length of 48 

" Grossmann's, Analyzed 31 

" '• Cut-off 108 

" Wooden Compensation 112 

" to Make ....143 

Pendulums 2«0 

Pendulum Essay 169, 228, 246, 275 

Pinion Measurement 62, 115, 214 

Practical Education 73 

Patience . 92 

Plating Iron with Copper 120 

Protecting Stones in Soldering 135 

Peddlers. ' 213 

Polishing . 215 



PAGE 

Polishing Brass Work 24ft 

Prevention of Rust on Steel 283 

R 

Repairing Watches 116, 186 

Regulating Watches 144 

Rims, Worn ". 135 

Reminiscences of an Apprentice 256, 273 

Rose Drill 47 



Soft Solder 44, 125 

Silver Blanching 47 

Staking Tool 64, 94, 113, 179 

Suggestions to Watch Manufacturers 76 

Swing Rest .'. 119 

Sizing Pinions 214, 262, 263 

Silver-Cleaning Solution 283 

Straightening Arlwrs 283 

Steel, to Prevent Rusting 283 



Transit, to Adjust 46 

" Bliss' 61 

Trifles 68 

Taking in Work : 77 

Taps and Drills . . . 115 

Travelling Opticians 163 

Thermometer Irregularities r 254 

Tenacity of Metals 96 

Time Ball 28a 

u 

U. S. Watch Factory 71 

Using Benzine instead of Alcohol 284 



Vibratory Motion of Earth Crust 248 

w 

Wheel Teeth, Addendum by Co-ordinates. 126 

Calculation .' 19 

" Finding Numbers 238 

Workmen, The Coming 36 

Watch Cleaning 45 

Workmen, Their Improvement 49 

Watch Repairing 68, 210 

WoikBsnch 72 

Watch Hands. Red 95- 

Brass 236 

" Book 238 



CONTENTS. 



No. I.-JULY. 



PAGE 

Improved Mercurial Pendulum 1 

Letter from J. Herrmann 4 

Chronometer Escapement 6 

Influence of Electricity and Earth Magnetism 12 

American Horological Journal 13 



Isochronal Adjustment of Balance Springs 14 

Calculation of Wheel Teeth 19 

Dialing 21 

Method of Determining Distances 23 

Equation of Time Table 24 



No. II.-AUGUST. 



Chronometer Escapement 25 

Mr. Grossmann's Pendulum Analyzed 31 

Heut 34 

The Coming Workmen 36 

Isochronism : 39 



Dialing 



40 



Watch and Clock Oil 43 

Soft Solder 44 

Watch Cleaning 45 

Answers to Correspondents 46 

Equation of Time Table 48 



No. Ill.-SEPTEMBER. 



How can the Condition of the Coming Workman be 

Improved 49 

Heat 51 

Dialing 55 

Adjustment to Temperature and Position 58 

Jew elling 59 

John Bliss & Co.'s Improved Transit Instrument 61 

Pinion Measurement C2 



Ortho-Chronography 63 

New Staking Tool 64 

Jean Paul Gamier 64 

Industrial Exposition in Altona 67 

Trifles 68 

Answers to Correspondents 68 

Equation of Time Table 72 



No. IV.-OCTOBER. 



Practical Education 73 

A Suggestion to Watch Manufacturers 76 

Taking in Work 77 

Heat 78 

Explanation of Astronomical Terms relating to Time. . 81 

The Lever Escapement 83 

Dialing 87 



Patience .. 92 

Garlic Juice vs. Magnetism 93 

N. Y. Watch Co 93 

Staking Tools 94 

Answers to Correspondents 94 

Equation of Time Table 95 



No. V.-NOVEMBER. 



Invention 97 

Heat 99 

The Lever Escapement 102 

Adjustments to Positions, Etc 105 

Mr. Grossmann's Mercurial Pendulum 108 

Files 109 

A Compensated Wooden Pendulum 112 

Staking Tool 113 



Benzine as a Substitute for Alcohol 114 

Taps and Drills 115 

Pinion Measurements 115 

Repairing English Watches 116 

Fair of the American Institute 116 

Answers to Correspondents 119 

Equation of Time Table 120 



No. VI.-DECEMBER. 



Heat 121 

Soft Solder 125 

Construction of the Addendum of a Train Wheel Tooth 

by Co-ordinates 126 

Adjustments to Positions, Etc 129 



Hair-Spring Gauge 134 

Transit Instruments 134 

Worn Rims 135 

Light 135 

Answers to Correspondents 140 



Engraving 133 j Equation of Time Table 144 



IV 



CONTENTS. 



No. VII.-JANUARY. 



Essay on the Construction of a Simple and Mechanically 

Perfect Watch— Chap. I . 145 

Adjustments to Positions, Etc 152 

Engraving on Jewelry and Plate 158 

Metals 160 



Travelling Opticians. . , 163 

Light 165 

Answers to Correspondents 168 

Equation of Time Table 168 



No. VHI.-FEBRUARY. 



The Pendulum 169 

Heat 175 

Measuring Hair-Springs 179 

Abstract of Rates of Chronometers 180 

Metals and Alloys 184 



Hints to Repairers 186 

Light 188 

Answers to Correspondents 191 

Equation of Time Table 192 



No. IX.-MARCH. 



Essay on the Construction of a Simple and Mechanically 

Perfect Watch 193 

Correction 200 

Heat 201 

Brass Alloys 204 

Light 207 

Hints to Repairers 211 



Good Time , . 213 

Donation to the Museum of the Land Office 213 

Jewelry Peddlers 213 

Query 214 

Answers to Correspondents 215 

Equation of Time Table 216 



No. X.-APRIL. 



Essay on the Construction of a Simple and Mechanically 

Perfect Watch 217 

Heat 223 

The Pendulum as Applied to the Measurement of Time. 228 



Nickel 234 

Watch Brass 236 

Answers to Correspondents 238 

Equation of Time Table 240 



No. XI.-MAY. 



Essay on the Construction of a Simple and Mechanically 

Perfect Watch 241 

The Pendulum as Applied to the Measurement of Time. 246 

Vibratory Motion of the Crust of the Earth 248 

Alloys of Gold 249 

Enamels 252 



Thermometer Irregularities 



Reminiscences of an Apprentice 256 

A Few Words on Pendulums 260 

Hardening Steel 262 

Sizes of Pinions 262 

Answer 263 

Monograms 264 



254 Equation of Time Table 264 



No. XH.-JUNE. 



Essay on the Construction of a Simple and Mechanically 

Perfect Watch 265 

Alloys of Gold— No. 2 271 

Reminiscences of an Apprentice — Making Pins 273 

The Pendulum as Applied to the Measurement of Time. 275 



Monogrammatic Art fS2 

Answers to Correspondents 283 

The Horological Journal 284 

Equation of Time Table 284 



AMERICAN 



Horological Journal. 



Yol. n. 



NEW YORK, JULY, 1870 



No. 1. 



CONTENTS. 

Improved Mercurial Pendulum, 1 

Letter from J. Herrmann, 4 

Chronometer Escapement, 6 

Influence of Electricity and Earth Magnetism, 12 

American Horological Journal, 13 

Isochronal Adjustment of Balance Springs, . 14 

Calculation of Wheel Teeth, 19 

Dialing, 21 

Method of Determining Distances, 23 

Equation of Time Table, 24 

* m * Address all communications for Horological 
Jottbnax to G. B. Miller. P. 0. Box 6715, New York 
, Office 229 Broadway, Room 43. 



A NEW IMPROVED MERCURIAL PENDULUM. 



No. 11 of your Journal contains a commu- 
nication from Mr. Coffinberry, treating of 
compensation pendulums. I perfectly agree 
with Mr. Coffinberry, that it is a great draw- 
back in the mercurial pendulum, that the 
greater diameter of the column of mercury 
prevents its being affected and penetrated by 
changes of temperature as quickly as the 
comparatively thin rod which it is intended 
to compensate. But besides this, there is a 
defect of much more serious character in this 
pendulum, arising from the different heights 
in which the compensating parts of it are 
situated ; the one extending from the point 
of suspension to about f of the total length 
of the pendulum, while the other occupies a 
short part of the lower end. A simple experi- 
ment will give evidence that these two com- 
pensating elements are existing in essentially 
different temperatures. If you suspend two 
thermometers on a wall, the one three feet 
higher than the other, it will be found that 
in an artificially heated room the upper ther- 
mometer shows about 3° R. (=7 Fahr.) 
more heat than the lower one, in accordance 
with well known physical laws. For these 
two combined reasons, the mercurial pendu- 
lum which performs admirably in an astro- 



nomical observatory, generally fails in parlors 
and inhabited rooms. In this particular 
point the gridiron pendulum offers better 
chances, because its compensiting elements 
accompany each other nearly in their entire 
length. 

Theoretically, the mercurial pendulum is 
the most perfect compensation, performing 
entirely without any frictional resistance, 
whereas the gridiron pendulum is, to a cer- 
tain extent, liable to acting by jerks ; for it 
can be seen that each expansion of the rods 
is at first checked by the friction in the 
traverse pieces, and produces a slight de- 
flection of the rods, till the tension of these 
latter overcomes the friction. 

Considering the great advantages to be 
hoped from the general employment of the 
mercurial pendulum, only checked by its 
above-mentioned deficiencies, I thought it an 
object well deserving earnest study, and 
made it long since the theme of my medi- 
tations in my leisure hours. I hope it will 
not be without interest for your readers to 
have the results placed before them, and I 
also trust that those horologists who have a 
rich experience in this matter will not think 
me arrogant when I state it as my opinion 
that Graham's mercurial pendulum is open 
to essential improvement. The question to 
consider is, whether the above-mentioned im- 
perfections are inseparable from the nature 
of the mercurial pendulum, and I think the 
best way for investigating this matter will be 
to treat it analytically. 

1. /->• there any reason or necessity for con- 
structing the mercurial pendulum with only one 
jar t. 

According to my opinion, there is not the 
slightest necessity for it ; on the contrary, 
several important advantages may be ex- 
pected by distributing the mercury in more 
than one jar. The latter will then be thinner 
and expose a greater surface to the surround- 



AMERICAN HOEOLOGICAL JOURNAL. 



ing air, and thus the mercury will be more 
sensitive to any change of temperature. 
Besides, there is not so much resistance 
opposed to a thin jar cleaving the air as to 
a thick one, and also the eddying of the mer- 
cury in a small jar is nothing compared to 
that in a wide one. 

It is surprising, however, that notwithstand- 
ing these evident deficiencies, the mercurial 
pendulum of Graham's arrangement has 
maintained itself in so great favor in Eng- 
land. The French have been more aware of 
its weak points, and their best makers con- 
struct their mercurial pendulums with 4 jars. 
The mercurial pendulum of Mr. Winnerl 
(Paris) has 4 glass jars and may be called a 
good arrangement. In Saunier's " Treatise 
on Modern Horology," of which you speak 
in some of your last numbers with well- 
deserved praise, there is an illustration and 
short description of the mercurial pendulum 
of Mr. S. Vissiere (Havre), constructed with 
the same number of glass jars, but striking 
by the exquisite grace and elegance of its 
arrangement, without sacrificing any scienti- 
fic advantage, as any one may suppose who 
is acquainted with the leading principles of 
Mr. Vissiere in his horological productions. 
I also saw by the kindness of an horological 
friend in the United States some small wood- 
cuts of clocks manufactured by Messrs. How- 
ard & Co., Boston. Their mercurial pendu- 
lums have 3 jars, and show that they have 
also emancipated themselves from the Gra- 
ham tradition. 

2 What material is most suitable for making 
the jars? 

Most of the English makers prefer iron. 
Some have a jar of cast-iron, which I do not 
think altogether safe, on account of the 
porosity of this material, and the readiness 
with which mercury penetrates through the 
smallest openings. This point, however> 
seems to be settled by experience. "Wrought- 
iron or steel is more desirable, and in our 
time there is hardly any difficulty in getting 
it of a proper shape for the purpose. Most 
of the other metals are out of question here, 
because they enter into chemical action with 
mercury — even gold and silver not excepted. 
Glass jars give a nice appearance to the 
pendulum by exhibiting the metallic gloss of 



the mercury, and at the same time its height 
and movement in the jars. They also facili- 
tate the detection of the air bubbles in the 
mercury, so injurious to the effect of compen- 
sation, which can only be avoided by the 
utmost care in filling the jars. Glass, on the 
other hand, is rather liable to injury, rather 
difficult to get of uniform thickness through- 
out, and what may be considered the worst 
of all, it is a bad conductor of heat, thereby 
retarding the effects of temperature on the 
mercury. It has been said in favor of the 
glass that its expansive ratio is much below 
that of iron, and hence the effect of the linear 
dilatation of the column of mercury not so 
much lessened in the glass jar, and conse- 
quently the height of mercury required in 
the glass jar will be less than that which an 
iron one would necessitate. This ai'gument 
weighs not very heavy, for I conclude from 
the circumstances above exposed that it is 
desirable to have the mercury columns of the 
greatest height attainable. Besides, the ex- 
pansive ratio of glass is rather variable 
according to its composition, while that of 
iron is more reliable. 

For these reasons I incline to the belief 
that iron jars are preferable for a mercurial 
pendulum for scientific purposes. If brass 
and zinc were not liable to deterioration by 
mercury they would be better still, because 
their greater expansive ratio demands a still 
more increased height of mercury. 

3 What material is best adapted for the pen- 
dulum rod ? 

In this particular point, so far as I know 
of, all makers coincide in the employment of 
steel. Steel is a very rigid material and there- 
for requires but little thickness to make a 
sufficiently solid rod. The expansive ratio of 
steel is one of the lowest of all the metals 
which might be thought of for this purpose. 
Thus, if a thin rod and a short column of 
mercury were wished for, there would un- 
doubtedly not exist any better material for 
the rod than steel. But it seems that we 
ought to search for the contrary in order to 
improve the mercurial pendulum, for the con- 
ditions of compensation will be all the better 
if the rod is of the same thickness, or nearly 
.so, with the jars, and if the columns of mer- 
cury are of the greatest height obtainable. 



AMERICAN HOROLOGICAL JOURNAL. 



From this point of view, I thought I would 
select a material of great expansive ratio; and 
of all metals practically applicable here, zinc, 
expanding three times as much as steel, will 
answer best. The very inferior strength and 
rigidity of this material is no impediment to 
employing it, since we consider a thick rod 
advantageous for a uniform penetration of 
the compensating elements by the changes of 
temperature. The liability of the zinc rod to 
bending may be overcome by making it a 
drawn hollow tube and inserting a rod of iron 
or steel inside. 

This arrangement, by the greater weight of 
the rod and by the required increase of height 
of the mercury columns, tends to raise the 
centre of gravity of the pendulum, which at 
the same time is its centre of oscillation, ma- 
terially higher than it is situated in Graham's 
mercurial pendulum, and consequently a pen- 
dulum constructed on the principles above 
described, for vibrating seconds, must be es- 
sentially longer than Graham's. But even this 
is no disadvantage, especially in the United 
States, where a taste for clocks with large 
dials prevails, for the pendulum ought to be 
as much as possible in proportion to the dial. 

4. What relative size of jar is the best ? 

When employing three, foiir, or more jars, 
it might seem advantageous to make the mid- 
dle of greater diameter than the outside ones, 
in order to diminish the resistance of air to 
the vibrating movement of the pendulum. 
This advantage, however, is of no great im- 
portance, because the resistance of the air is 
very nearly a constant figure, and, on the 
other hand, it would be a serious impediment 
to a good compensation if one or several of 
the jars were wider than the other ones, be- 
cause their contents would not receive changes 
of temperature with the same readiness as 
the others. Besides, the different capillarities 
of the jars might also introduce irregularities 
not easily accessible to calculation. There- 
fore I think it best to have all the jars the 
same width. A mercurial pendulum thus 
arranged will certainly be much less under 
the influence of the resistance of air than one 
with only one jar. 

The above considerations have led me to 
the construction of a new mercurial pendu- 
lum of about the following dimensions : 



kilogs. millm. Eug. in. 

Weight of mercury columns. 450 = 17.7 

Diameter 16.5 = 0. G5 

Weight of mercury 5. 2 

Outer diameter of the 4 iron 

jars • 18.5 = 0.73 

Weight of the 4 iron jars ... 1.0 

do. frame 0.83 

Thickness of zinc rod 17.5 = 0.69 

Weight of do 1 73 

Total length of pendulum . . about 12.30 = 48.43 

Total weight 8.26 

It will be easily seen that this arrangement 
has the following advantages: 

1. Equal thickness of the compensating 
parts, and, in consequence of this, equal sen- 
sibility of the same to changes of temperatui'e. 
(The trifling difference between the diameter 
of zinc rod and that of iron jars or tubes will 
be made up by the greater heat-conducting 
power of the iron. ) 

2. Considerable diminution of the defect of 
compensation in the mercurial pendulum, 
arising from the difference of temperature in 
the different heights in which the compen- 
sating elements are moving. In Graham's 
mercurial pendulum the mercury constitutes 
about the sixth part of the length of the 
pendulum, while the rod, beginning above 
the mercury, makes up the other five-sixths 
of it. The above-described improved mer- 
curial pendulum has its zinc rod passing 
through the frame down to the lower end of 
the pendulum, and the mercury column con- 
stitutes more than one-third of the total 
length. 

3. Reduction of the resistance of the air to 
the least amount. 

The correction of the compensating power 
of a mercurial pendulum is rather trouble- 
some, especially for smaller differences, and 
besides the loss of time, it is always fol- 
lowed by an alteration of rate, owing to the 
addition or reduction of mercuiy. To ob- 
viate these difficulties, I have adjusted into 
the hollow of the top end of the zinc rod 
a rod of brass, carrying at its top end the 
suspension hook. This brass rod occupies 
a length of about three inches in the zinc 
tube, and both parts have a number of holes 
all through, in distances of about one-fourth 
of an inch, and exactly corresponding with 
each other. If a pin is put through the 



AMERICAN HOKOLOGICAL JOURNAL. 



topmost of these holes, the acting length of 
the zinc rod and consequently the compen- 
sating power of the pendulum is greatest. By 
transferring the pin to any lower hole, a 
corresponding length of brass is substituted 
for the same length of zinc, and thus the 
effects of compensation diminished. The 
expansive ratio of zinc and brass being not 
very different, this connection will be found 
sufficiently delicate for very small changes in 
the compensating power, while it is very easy 
to operate. 

I must confess that I have not had suffi- 
cient leisure yet to test the performance of 
the pendulum made according to these prin- 
ciples, but I think the theoretical principles 
of it safe enough. At any rate, I believed the 
matter of sufficient importance to submit it 
to the criticism of the horological community, 
after having taken the necessary steps for 
secui'ing patent rights for this improvement. 

MORRITZ GrROSSMANN, 

Watch Manufacturer. 
Galshute, Saxony, May 15, 1870. 



LETTER FROM MR. J. HERRMANN, OF LONDON. 

Editor" Horological Journal : 

Sir, — Permit me to thank you for the re- 
mittance of the Horological Journals, and 
the opportunity thus afforded me by your 
kindness to peruse their contents, which has 
been to my great pleasure and satisfaction. 

Apart from every sense of personal honor, 
I feel indebted to you for the notice you have 
bestowed on my paper, entitled The British 
Horological Institute, etc., in your valuable Jour- 
nal, and for the manner you have treated 
your extracts therefrom, in the March num- 
ber — that being the last I have — thereby 
supplementing my labors to effect the practi- 
cal adoption of a proposition from which I 
sincerely believe great benefit will acrue, and 
aiding my desire to see such extended upon 
perfect international principles to all horolo- 
gists. 

I cannot claim the honor of a visit to 
America, neither did I inquire for or take 
notice of any facts bearing on the subject, 
beyond those which were open to my person- 
al observation ; therefore, in as far as my re- 



marks apply to a state of things there, they 
are not due to any interest or purpose on my 
part, but simply to a coincidence of circum- 
stances. Believing that simple exposure of 
any evil, without the application of active 
stimulants for good, has rather a negative 
than a positive tendency, I had no object in 
parading these facts, further than to prove 
my position in advancing the proposition, 
that there is a need of better measures, and 
that the result it promises is desirable. 
Therefore I do not stop to inquire if the 
American horological trade is in a better or 
worse condition than the British or any other, 
but is it in any position that will still admit 
of benefit to its members, by the adoption of 
my proposition ? 

Eliciting an affirmative answer to this ques- 
tion from your Journal, I at once disregard 
all negative difference, looking for and desiring 
a positive equality. 

For this reason — having given this subject 
serious thoughts — I hope you, sir, and your 
readers will not consider me assuming if I 
state that I should be happy to address you 
again on this point at some future period. 

Your closing remarks in your article on 
Horological Institutes, page 274, running thus : 
"We would like to put this lecture of Mr. 
Herrmann's before every watch repairer in 
the land, and we are of opinion that there 
would be a large demand for works on geom- 
etry, and the American Horological Jour- 
nal," remind me of circumstances about 
which I would beg your indulgence for a few 
further observations. 

That the proposition will tend to a more 
scientific education among apprentices and 
workmen, is a principal point in its basis. 
That such tendency will result in a demand 
for channels of information, I have no doubt ; 
but I will not speculate with your valuable 
space about this question, nor inquire whether 
a horological workman requires such or not, 
asking you. sir, and your readers, for the sake 
of my argument, to grant the supposition 
(no matter whether real or assumed) that 
such is needful. Out of this basis rises the 
question : How is he to obtain it ? or how is 
such to be imparted to him ? I may here 
state, that I treat this question in a narrow 
sense ; that is, the diffusion of scientific 



AMEEICAN HOROLOGICAL JOURNAL. 



knowledge for practical purpose apart from 
intellectual cultivation ; although it must 
tend to this in effect, yet here I make it secon- 
dary Science is, so to say, a large garden, 
from which the bouquet of horological science 
is gathered. To do this presupposes a knowl- 
edge which cannot be possessed by an un- 
cientific workman, and hence, as this mat- 
ter stands, a horological student is compelled 
to study almost the whole of the sciences in 
order to find such problems, theories, and 
axioms, as are applicable to horology, and are 
of assistance to him in his daily labors. I 
should be the last to advise any workman not 
to acquire a knowledge of the whole of the 
sciences ; but this is of course an undertak- 
ing requiring labor and perseverance that 
very few would be inclined to devote to it. 
What, therefore, is necessary is to put a collec- 
tion of the sciences, applicable to, and apphed 
to horological objects before the workman. 
By such a method men of ordinary intellec- 
tual capacity and perseverance — both not 
being synonymous — would have an easy op- 
portunity to obtain some of the most useful 
scientific knowledge ; while at the same time 
none would be prevented from rising to the 
highest scientific eminence. 

For example : if I take up a book on me- 
chanical or civil engineering, I find that in 
the outset, the reader — or here better called 
student — is made acquainted with definitions 
of terms, and demonstrations of facts, upon 
which subsequent propositions and calcula- 
tions are based, so that it is possible for the 
student to comprehend all subjects under dis- 
cussion. If, on the the other hand, I take up 
any work on horology, I find a total departure 
from this method ; either it is endeavored to 
pursue a mode of explanation that is super- 
ficially intelligible throughout, or occasionally 
the reader is all at once brought face to 
face with scientific terms, and mathematical 
formulas, which will perplex and annoy him, 
but convey no meaning to him. If we con- 
sider the principle of the two methods for a 
moment, we shall easily detect the preemi- 
nence of the former over the latter. By the 
first, the student is supplied with a basis to 
reason out and calculate, and prove the the- 
ory and subjects as they are brought before 
him ; by the latter, he has no other means 



than to take for granted what he sees in 
black and white. Should proportions be 
given in plain figures, he then may prove them 
in solid material, which is a slow, tedious, 
and expensive method. By the first, all the 
powers of the intellect are employed; by the 
latter, memory only; hence the former is sci- 
entific education, while the latter never can 
be. For these reasons there is a special 
opening for horological publications, treating 
its subjects in such a manner ; it would open 
a new field of interest to many readers, and 
likewise so create a demand, and, on the whole, 
effect a large amount of good. 

It is upon this basis that I pursue my 
instructions to the classes at the British Horo- 
logical Institute. Having been apprenticed 
to the watch trade and engaged at it ever 
since, I have the advantage over a professed 
science teacher in a practical knowledge of 
what a workman requires ; hence, I put be- 
fore him first, the knowledge of such science 
only that he will require for horological sub- 
jects, and then its application. To give ex- 
amples would require no less than actual 
demonstration, for which I should have to 
give definitions or fall into the same fault that 
I have been condemning; therefore I conclude 
with this subject by a promise to send you an 
address upon technical instruction, delivered 
at the British Horological Institute, which 
will be published in next number, leaving you, 
sir, to make such use of it as you think it 
worth. Begging your indulgence for occu- 
pying so much of your valuable space, 
I am, Sir, 

Yours, etc., 

J. Herrmann. 
London, May 19, 1870. 

[We perfectly agree with Mr. Herrmann 
in his plan of imparting instruction, and hope 
he will take an early opportunity of stating 
his proposition more at length, believing that 
a large majority of our readers would gladly 
avail themselves of his practical teachings. 
So far as the "trade" is concerned in this 
country, their interest in the entire subject 
extends as far as their profits are concerned, 
and no farther ; but there are a large num- 
ber of intelligent woi'kmen who are seeking 
every means of self-improvement, and it is to 
them we look for a better state of things.] 



AMERICAN HOROLOGICAL JOURNAL. 



THE CHRONOMETER ESCAPEMENT. 



There is an opinion prevalent among a 
large number of the watch-carrying commu- 
nity, as to the chronometer escapement, that 
it is not the most reliable one for pocket use. 
The greater number of watchmakers, too, 
from having had troublesome experiences 
with it, are perhaps of the same mind. The 
argument for this opinion derives its greatest 
strength probably from the fact that so many 
pocket chronometers have failed to give satis- 
faction to their owners, because of their fre- 
quent stopping, or tripping, as it is expressed, 
and even experienced workmen have often 
failed to remedy the evil. While such is the 
case, it is nevertheless well known that among 
the best manufacturers of the world the good 
chronometer is considered as their finest pro- 
duction; that only the most skilful workmen 
are intrusted with them, and that wherever 
the most reliable time is required, the chro- 
nometer is used. It is admitted that for sta- 
tionary use it is all that, but for pocket use, 
where it is necessarily subject to irregular 
external influences, it is claimed that other 
escapements, the lever particularly, is much 
better suited. This might be tested, and the 
reputation of the good chronometer vindica- 
ted as not any more liable to err under the 
same circumstances; but that is not the object 
of this article. 

Now, it is the writer's conviction, that the 
cause of so many chronometers being trouble- 
some to the wearers has its foundation in an 
erroneous construction of some of the parts 
of their escapements; and the reason why so 
many workmen are unable to remove it lies 
in the misfortune of their not possessing a 
knowledge of the correct principles of the 
escapement; hence are not able to detect 
faults, particularly when such are primary 
ones. It is to this class of chronometers that 
the following is devoted, and respectfully sub- 
mitted to the reader. 

Not all chronometers are troublesome, and 
this alone ought to lead the workman to re- 
flect. Next, we can easily distinguish the 
make and class of chronometers which are 
troublesome, and that will give us the means 
of comparison. Badly constructed escape- 
ments will often go for a long time without 



stopping or giving any trouble, and therefore 
the mere running of a watch cannot be taken 
as a proof of its being correctly built ; but 
when a watch does stop it is a positive evi- 
dence that something about it is not right, 
and the workman will not be able to discover 
the wrong unless he has a correct standard to 
compare it with. 

The escapement, when correct, is, like every 
other part of the watch, constructed accord- 
ing to correct geometrical and philosophical 
principles, the knowledge of which can be the 
workman's only safe standard. Now there 
are a number of chronometers of different 
makers, among which the well-known " Cow- 
deroy" and "Dixon" are perhaps most prom- 
inently known as troublesome ones. If we 
take one of these and compare it with a 
"Frodsharn," a " Jurgensen," or with one of 
Morritz Grossniann's model chronometers, as 
samples, we will find, if everything else in 
the construction of the escapement as to prin- 
ciple is alike, a difference in the shape and 
form of the impulse roller. The illustrations 
will show that difference and serve to ex- 
plain the consequences thereof. 

Fig. 1 shows the development of the two 
main levers of the escapement and the shape 
of the roller, according to sound principles. 
For any given centre distance of escape wheel 
and balance, with a view to obtain a certain 
amount of leverage, the relative sizes of wheel 
and roller are found in the following man- 
ner : 

It is desired to obtain a leverage impulse of 
40°. G, the centre of wheel, and C, the centre 
of the balance, are connected by a line, T, the 
distance of which may be ad libitum. The 
wheel has fifteen teeth, therefore the distance 
between the points of two teeth is 3 T y> °=24°. 
These 24° are laid out by means of a protrac- 
tor to 12° on each side of the line T, and indi- 
cated by lines a. Now in addition to the 40° 
impulse desired, there must be added 5° for 
the necessary fall, making together 45°, which 
are also laid out equally on each side of the 
line T, but from the centre c, and marked by 
lines b. Through the points of intersection 
of these four lines, circles are drawn from the 
centres G and C, in the peripheries of which 
the exact proportionate sizes of roller and 
wheel are found. The roller jewel, L, must be 



AMEEICAN HOKOLOGICAL JOUENAL. 



set so that its leverage surface, o o, exactly 
coincides with a straight line to the centre of 
the roller. 

The inclination of the teeth of the wheels 
to a straight line from the centre of the 
wheel is generally from 25° to 27° (in dia- 
gram 26°), and from this it will be seen that 
when the roller jewel comes to the position 
of 5° in front of the tooth, at which time the 



unlocking of the detent takes place and the 
wheel falls, the two front surfaces of tooth 
and jewel will exactly coincide; the tooth will 
neither fall on its point nor with its front 
surface on the point of the jewel, either of 
which cannot but be injurious. 

Now for the hollow in the roller which per- 
mits the passage of the tooth during the 
impulse ; and here is where the troublesome 




chronometer is generally found wanting. The 
hollow must be deep enough to allow a tooth 
of the wheel to pass through without touch- 
ing, must extend over an arc of the circum- 
ference of the roller of 45° (or the degrees of 
leverage obtained) and be distributed so that 
two-thirds of it will be from o, the point of 
the roller jewel, to m, the commencement of 
the hollow, and the other third from o to n, 
back of the jewel, which will give a space of 
90° hollow in front of the jewel and 15° on 



the back of it. The philosophy of this is as 
follows : When the balance is slowly moved 
in the direction from m to n, and the unlock- 
ing jewel in the small roller forms the requi- 
site angle with the impulse jewel in the large 
roller, the tooth in waiting for the impulse 
will always fall upon the jewel when 5° in 
front of it ; but when the balance is allowed 
to move freely, the velocity which it attains 
after a few impulses will carry it beyond that 
point, and the tooth will fall through more 



8 



AMERICAN HOROLOGICAL JOURNAL. 



than 5° of the arc of the roller. Now it must 
be borne in mind that the whole movement 
of the wheel is intercepted between each suc- 
cessive vibration of the balance, and that, 
however small that may be, the motive power 
has to overcome a certain amount of inertia 
in the train after every interception, during 
which time the balance is moving at an 
increased rate. Suppose, then, the vibration 
of the balance to have increased to arcs of 
400° or more ; the velocity with which it moves 
then, taking into consideration, too, that it 
becomes greatest at the centre of oscillation, 
which is the point where the jewel passes the 
wheel tooth, will probably carry it to or be- 
yond the line of centre of impulse before the 
tooth actually gives the impulse, or even 
actually falls. In that case the tooth will be 
22^° of the arc of the roller behind the im- 
pulse jewel, and will require that much or 
more hollow in the roller in front of the jewel 
in order to clear the point m of the roller in 
its fall ; for perfect safety 30° is given it. 

By a glance at Fig. 2, which is as near as 
possible a true representation of the shape of 
the roller, as well as the position of the im- 
pulse pallet of those troublesome chronom- 
eters, and comparing the above principles 
with it, it will at once be apparent to the work- 
man what the whole difficulty is, and what 
must cause their tripping. 

In Fig. 2, the jewel B is so placed that the 
centre of it (not the leverage surface) is in a 
straight line to the centre of the roller ; and 
in A it is still worse, standing at an angle to 
the Hue, on account of which it will dig out 
the front surface of the tooth when receiving 
the impulse ; both have but 30° or little more 
hollow, which at B is divided in half by the 
front surface of the jewel, and at A not much 
better. If now, under the above described 
circumstances, the jewel will, by reason of the 
velocity of the balance be, carried to the line 
of centre or beyond before it receives the 
impulse, both Mall inevitably collide at the 
point m of the roller and the tooth about to 
give the impulse, having but 15° or little more 
clearance ; and hence it is that such chronom- 
eters will trip more easily when the vibra- 
tions of the balance are increased. Now it 
may be that many chronometers with rollers 
as in Fig. 2 do not stop ; if the train of the 



watch is a good one, and every thing else per- 
fect so that there is no impediment to a free 
and perfect transmission of the motive power, 
it may go without stopping ; but the roller is 
nevertheless constructed badly, and when a 
watch does stop with such a roller, in all 
cases a new one must be made, to insure suc- 
cess. 

There may be other defects in escapements 
which may cause their stopping, but seldom 
such radical ones, as the above. The little gold 
unlocking spring on the detent must be long 
enough, so that its angular motion effected 
upon it by the small roller will insure a per- 
fect unlocking, yet not so much as to inter- 
fere with the free vibration of the balance any 
more than cannot be avoided. The locking 
surface of the jewel in the detent should form 
an angle of 12° with a straight line from the 
centre of the wheel, but in Swiss chronom- 
eters, where the locking jewel takes the 
second tooth of the wheel from the roller, and 
the line of the detent back of the jewel forms 
at the locking point a right angle with a line 
from the centre of the wheel, the locking sur- 
face of the jewel must be almost in a straight 
line to the centre of the wheel, and in the 
best escapements it is found to be so. In all 
cases the end of the unlocking spring must 
point directly to the centre of the balance 
staff when at rest, and to whatever curve it 
may have been necessary to bend it to suit 
circumstances, the extremity of it, which is 
acted upon by the unlocking jewel in the 
small roller, must again coincide with the 
straight line of the detent back of its jewel. 
The tooth of the wheel at rest upon the lock- 
ing jewel in the detent, should never take 
more than one-fourth of the width of the 
jewel. Never work at the detent spring of a 
chronometer, unless the above conditions are 
not found in it ; one which has never been 
meddled with is generally in order, for a work- 
man who is not able to make one right, would 
not be employed by manufacturers on such 
escapements. 

When an escapement of the preceding 
troublesome class is to be remedied, a new 
roller must be made. The workman who is 
called upon to remedy it may not have any 
experience in making them ; and as the writer 
would recommend to such to learn how to 



American horological journal. 



make them, he will proceed to give him the 
necessary instructions. 

First of all, the exact size of the roller must 
be determined ; for this, I would not trust to 
the size of the old one, but proceed in the 
following manner — premising that the work- 
man is provided with standard measures on 
the metric system, as by far the most con- 
venient ones : Measure the diameter of the 
wheel accurately (the tables of measurement 
in Grossmann's prize essay on the lever escape- 
ment, which every workman ought to possess, 
will greatly facilitate this); increase its dia- 
meter by ten or twenty times, and draw on 
paper a circle of the diameter of such in- 
creased size ; then measure the distance from 
the centre of the wheel, the pivot-hole, to the 
pivot-hole of the balance staff with a good 
depthing tool, and increase it also by ten or 
twenty times, and indicate such increased 
distance by a line drawn from the centre of 
the circle outward, and call it line T as in 
Fig. 1. Now, as in Fig. 1, lay out by means 
of a good protractor 24° from the centre of 
the circle to 12° on each side of the line T 
corresponding to lines a in Fig. 1 ; through 
the points of intersection of these lines and 
the circle, and from the outside end of the 
line T, draw the lines b, as also a circle, and 
you have found at once the amount of lever- 
age of the escapement and the size of roller 
required. Now measure the diameter of the 
last circle, which is the relative size of the 
roller, and divide it by ten or twenty, which- 
ever you increased the others with, and the 
quotient will give you the actual diameter of 
the roller required. The same accurate result 
could be obtained by trigonometrical calcula- 
tions, but would require much more experi- 
ence in calculation. The object of increasing 
the measurements, as will be seen, is simply 
to magnify the operation. Now set the ob- 
tained diameter of roller down so as not to 
forget it, together with the amount of lever- 
age found, the latter of which will be the 
necessary width of the hollow required for 
the roller. 

Next, take the best English round steel, of 
sufficiently larger size than the roller re- 
quired, so as to allow it to be turned up true ; 
saw a piece off and file it flat on both sides, 
and as near to an even thickness as possible. 



This piece must now be bored and turned up 
true, which, if the workman is provided with a 
foot lathe, can best be done on what is called 
a drum chuck. This chuck is illustrated in 
Fig. 3, and as it is an inestimably valuable 
appendage to the lathe, the workman should 
at once make one. Fig. 3 shows the side and 
front view of the chuck ; it is a common 
English barrel, fitted to a small lap chuck of 
the lathe so as to run perfectly true. The 
lid, as will be seen from the cut, can be re- 
moved for the purpose of cementing the 
work on to it, or examining the same. No 
better chuck could be used for making jewels, 
as the lid can be reversed and the other side 
of the jewel opened without removing it from 
the cement. For this purpose the seat for 
the lid in the barrel must run perfectly true, 
and this is accomplished in the following 
manner : First, turn the hole in the lid 
perfectly true on the universal lathe, and with 
as thin a cutter as will stand the pressure ; 
then gently stretch the outside of the lid by 
hammering it a little all around the circum- 
ference ; now turn up a common brass chuck, 
no matter of how much less diameter than 
the lid, so that on the end of it you have a 
projecting centre, like an arbor, perfectly 
cylindrical, and filling the hole in the lid 
accurately ; not too tight or loose, so as to 
allow it any play, and be careful that the back 
of the chuck which is intended for a bearing, 
is exactly at right angles with its sides ; and 
on to this chuck you now cement the lid with 
a little shellac, turning the spindle while you 
are cementing it, and taking care that you 
bring it solidly against the bearing of the 
chuck ; when cool, turn the circumference of 
the lid up square and true until it fits the 
barrel again, but not too tightly. When this 
is done, remove it ; put it into the barrel, 
centre it from the hole in the lid on the 
universal lathe again, and turn the lower hole 
true correspondingly. The lower surface of 
the barrel, as also the front surface of the 
lap chuck on to which you want to secure the 
barrel, must also be turned off perfectly true. 
This can best be done by means of a slide 
rest, if the workman has one with his lathe. 
Now, the chuck must be centred, and a hole 
bored into it sufficiently large to admit a plug 
that will, after being turned up true, fit the 



10 



AMERICAN SEROLOGICAL JOURNAL. 



lower hole in the barrel perfectly, so as not 
to have to be forced on, nor to have any play 
when on it. On to this chuck you now secure 
the barrel by means of three screws equidistant 
from each other, and in a common circle from 
the centre, and as far from it as conveniently 
can be done ; this done, pull out the plug 
which was used for a centre of the barrel, 
when the whole chuck is finished, and the 
workman will never regret the trouble of 
making it. 

If, then, the workman has such a chuck, 
the piece of steel intended for the roller must 
now be cemented on to the lid, which, for 
convenience, can be taken off; and care 
must be had not to put too much cement on ; 
move the piece a little to and fro while the 
cement is yet warm, applying at the same 
time a little pressure with a sharp steel, and 
leave it as near as possible in the centre of the 
lid ; then put the lid into the chuck, applying 
again a little heat to it, and centre it perfectly 
by the outside of the piece. It must now 
be bored ; and to obtain a perfectly true hole 
it should be finished, boring with a small 
fixed cutter used on the slide rest ; or if the 
workman has none to his lathe, he can re- 
move the lid and do the same on the universal 
lathe. The exposed side of the roller must 
now be turned up true, then cemented the 
reverse way to the lid, and the other side 
turned true ; taking care that it remain 
still thick enough for grinding and polish- 
ing. 

When this is done, the piece must be re- 
moved, cleared of the cement, and another 
common brass chuck must be turned up 
somewhat smaller in diameter than the re- 
quired size of the roller when finished, and 
in the same way as before done, for the pur- 
pose of turning up the barrel lid true — the 
arbor point at the end of it fitting the hole in 
the roller (which must previously have been 
very nearly adjusted to the balance staff), so 
that it will go on without forcing, and come 
up square against the bearing of the chuck ; 
cement the roller on to it, and turn it to very 
nearly the calculated diameter. If the work- 
man has no foot lathe, the whole operation 
can be performed with equal precision on the 
universal lathe. The roller must now be 
removed from the chuck, cleared again from 



cement, and the incision for the place of the 
jewel must be cut. This should be done on a 
gear cutting machine, if the workman can get 
access to such an one ; and with a cutter 
which will make an incision as wide as the 
jewel is thick, so that it will fit in without 
forcing. Examine the machine, whether the 
axis of the spindle, which holds the cutter 
is perfectly horizontal, and at right angles with 
a line through the centre of the machine. 
Now, through the centre of the roller 
draw a line all across the upper surface 
with a sharp steel ; secure it upon the 
centre of the machine so that this line 
will coincide with a line through the centre 
of the machine and at right angles with 
the cutter spindle; set the latter so that the 
cutter will make the incision on the right 
hand side of the line across the roller and 
just grazing that line ; move the rest which 
carries the cutter spindle up so that the cut- 
ter will just touch the circumference of the 
roller, then mark on the base of the machine 
on which the rest moves the place by a sharp 
line drawn across the bar, and move the 
rest up towards the roller by the feeding 
screw just the length of the jewel, and pro- 
ceed to cut the incision by one single cut. If 
the workman cannot have access to a gear 
cutting machine, he can do it in the following 
manner : Prepare two little steel bars, file 
them flat to pretty nearly the thickness of the 
roller, make them perfectly straight and 
square, and after hardening them, smooth 
one side of each by grinding them on a 
smooth flat stone, then lay them over the rol- 
ler, so that the smooth sides will face each 
other, and one of them just up to the line on 
the roller, the other parallel to it, just the 
distance of the thickness of the jewel from it, 
and fasten them in the vice, leaving the rol- 
ler to extend above it (the vice) just the length 
of the jewel; then with a saw of the right 
thickness the incision can be made, care 
being had that it be made on the right side 
of the line across the roller ; when this is 
done, a hole must be bored through the rol- 
ler directly opposite the centre of the hollow 
which is to be made for the purpose of ena- 
bling you to poise the roller. It should be 
made as far from the centre as possible with- 
out breaking out into the circumference of it; 



AMEKICAN HOKOLOGICAL JOUKNAL. 



11 



and here it must be remembered that the 
point of the jewel must be exactly in the cir- 
cumference of the roller which has been ob- 
tained by calculation, and the roller after- 
ward polished so much smaller, that when it 
is in action the wheel teeth have one degree 
play. The roller is now ready (if the jewel 
fits it rightly) to be hardened and blued. 
"When tempered, the next thing to be 
done is the polishing of the circumference; 
this should be done on a live spindle, 
and on the same chuck upon which it 
was turned up, and by means of a swing 
frame attachment, as described on page 118, 
No. 4 of the Journal (and this is another 
appendage to the lathe which every workman 
should make or have made). There are other 
ways of polishing up a circumference true, 
without a lathe, but much more troublesome; 
and as pretty nearly every watchmaker now 
has a lathe of some kind, or ought to have 
one, the writer thinks it unnecessary to de- 
scribe them. When the circumference is 
polished, as well as the edges taken off and 
polished, the roller must be finally adjusted 
to the balance staff. Next, the hollow in the 
roller must be made, and to do this right, 
the workman may proceed in the following 
manner : As before stated, the hollow must 
extend over an arc of the roller equal to the 
amount of the degrees of leverage in the 
escapement. Now, an arc of such extent 
must be measured off on the roller in this 
way : Suppose it is an arc of 45°, then 360° 
are to 45° as the circumference of the circle 
to the length of the arc ; we can find the cir- 
cumference of the roller by measuring its 
diameter and multiplying it by 3.141592, then 

UjTjp X 45°. Or, by another rule : The cir- 
cumference of a circle whose diameter is unity, 
is 3.141592 ; if we divide this number by 360 
we shall obtain the length of an arc of one 
degree = 0.0087266. If we multiply this 
decimal by the number of degrees in the 
arc, we shall obt ain the length of that arc in 
a circle whose diameter is unity ; and this 
product, multiplied by the diameter of another 
circle, will give the length of an arc of the 
given number of degrees in that circle. 
Therefore, 0.0087266 X ^ = 0.392697 ; this 
decimal multiplied by the diameter of the 



roller will give the length of an arc of 45° in 
millimetres and hundredths of millimetres. 
This length obtained, mark off on the roller 
so that two-thirds of it will come in front of 
the impulse jewel, and the other third on the 
back of it. This done, cut into a pair of old 
tweezers a V; place the roller between them, 
so clamping it together with a pair of tongs 
that not quite the whole length of the arc to 
be cut will be exposed by reason of the V, 
and start the hollow with a good half round 
file till pretty nearly the length marked off. 
Now turn up a chuck in the lathe to a little 
less than the diameter of the roller, and 
cylindrical ; apply oil-stone dust and grind 
the hollow out until it is almost the right 
size, holding the roller firmly in a pair of 
tongs against it, and then finish by polishing 
with rouge or any of the polishing materials, 
and you will obtain a perfectly circular hollow 
and highly polished. The roller must now 
be poised on the balance by means of the 
hole which was bored into it and which is 
opposite the hollow, then the sides polished, 
finally the jewel cemented in with shellac, and 
it is done. 

Now, all this has taken more time to write 
than it really would to perform the work 
described ; but it must be remembered that 
it is intended for the benefit of those who 
wish to learn, not for the learned; and yet it 
will require all the application of a thinking 
workman to follow it out in practice. The 
workman may find it slow work at first, but 
he must be patient. A watchmaker, above 
all other mechanics, ought to be provided 
with an extraordinary amount of patience, 
and from the almost microscopic accuracy of 
the work he has to perform, his very nerves 
must gradually become trained for the utmost 
carefulness. A man who is not careful, and 
has no patience, will never make a good work- 
man ; but he who can justly be called a good 
workman, is an artist of no common order. 
Do not think you will never become a good 
workman because you cannot do work fast. 
We hear men boasting of how quickly they 
can do such and such delicate piece of work, 
and there is an impression on some people's 
minds that the fastest workmen are the best. 
Don't believe it; he who knows by experience 
what it is to do a piece of work well, will 



12 



AMEKICAN HOKOLOGICAL JOUENAL. 



always think it slow work. Work as fast as 
you can, but work well first. 

Th. Gribi. 
AVilmington, Del. 



INFLUENCE OE ELECTRICITY AND EARTH 
MAGNETISM. 



Having in a former article expressed the 
idea that the hair-spring, as well as the bal- 
ance, was affected by electricity, I have since 
gathered the results of experiments made in 
Prance and England on the subject, and shall 
present them to your readers if you deem it 
acceptable. One of these facts is given by 
Mr. Vissieu, an eminent French chronometer 
manufacturer, who says: " From the 26th of 
June, 1861, having four chronometers in 
course of rating, I noticed a progressive ten- 
dency to slow running (up to the 1st July the 
weather had been cloudy and stormy), and at 
first thinking that my astronomical clock was 
out of order, I made my sidereal observations 
with a transit and a repetitor circle of Borda, 
and my observations did not show any differ- 
ence in the running of the clock. From the 
1st of July, and after a heavy thunder-storm, 
the four chronometers came gradually back to 
their first running. This effect was illustra- 
ted more plainly on board of the steamship 
New York, whose chronometers were in ad- 
vance 33' 58" on her arrival at Liverpool, in 
consequence of the ship having been struck 
by lightning." 

And from the Nautical Magazine I compile 
the experiments of MM. Arnold and Dent, 
on two chronometers where the hair-springs 
were gold and the balances platinum, silver, 
and brass. 1. These two chronometers gave 
tinder the influence of earth magnetism, a 
variation twice less than common chronome- 
ters. 2. Under the influence of magnetized 
iron cars, this variation was scarcely percep- 
tible, while other chronometers showed a 
variation of several minutes. Two other chro- 
nometers, one having a gold hair-spring, the 
other a platinum and brass balance, gave 
mixed results, the magnetic effect seeming to 
be pretty nearly equalized between the bal- 
ance and hair-spring. 

A celebrated artist of Switzerland, F. 



Houriet, having constructed a chronometer 
entirely without steel, except the main-spring 
and the several staffs, it was submitted for 
six days to the action of a magnet able to lift 
a weight of 30 lbs., and no difference could 
be detected in the rate. The learned Ansart- 
Deusy, professor in the Naval Imperial School, 
sums up a report to the French Academy by 
saying that the only remedy for the variations 
produced on chronometers by their place on 
ships, is to use gold or any other metal but 
steel for manufacturing hair-springs. This 
fact has been demonstrated by the regularity 
of the rates in the chronometers made by TJ. 
Jurgensen, who uses exclusively gold for 
hair-springs. 

The practical application of these facts, col- 
lected from all parts of the civilized world, 
seems to suggest the use of another metal than 
steel for hair-springs. Gold, though very 
serviceable in ship chronometers, is too heavy 
for making flat springs, and cannot practically 
be used in watches. The question, then, would 
be, to find a metal not any heavier than steel, 
and as elastic, though the greatest trouble is 
to find a metal as handy as steel for manufac- 
turing, as most of the compound metals are 
uneven in texture, and so brittle that they 
require frequent annealing, thereby increas- 
ing greatly the cost of manufacturing. An- 
other practical deduction to be drawn from 
this known effect of electricity and magne- 
tism on time-keepers is, that no iron or steel 
should be carried in the watch pocket, since 
it is well known that a common knife blade 
will produce a strong deviation on the mag- 
netic needle. 

Ernest Sandoz. 

N. Y. Watch Factory, 
Springfield, Mass. 



$ST The New York "Watch Co.— "We are 
glad to learn that this Company have so far 
recovered from the effects of the fire as to be 
again producing watches, and will in the 
future be able to supply all demands for their 
goods. The greater portion of their small 
tools and material having been saved, as was 
also a building detached from the principal 
factory, their loss was much less severe than 
was first reported. 



AMERICAN HOROLOGICAL JOURNAL. 



13 



AMERICAN HOROLOGICAL JOURNAL. 

In presenting- the 1st No. of Vol. II. of the 
Horological Journal to Its friends, the pub- 
lisher desires to offer his grateful acknowledg- 
ment for the very nattering opinions of its 
merits, as expressed by the majority of its 
patrons -when renewing their subscriptions. 
"We confess to a feeling of pride in this matter, 
believing, as we do, that no journal published 
in this country has met with a more hearty 
endorsement from its readers. 

Having in the past allowed the Journal to 
make its way into public favor strictly on its 
merits as a practical and scientific exponent 
of the science of horology, we propose to con- 
tinue the same line of policy in the future, 
believing that the intelligent workman will be 
as sensible of whatever merits it may possess 
as though we indulged in any amount of self- 
glorification. 

We take great pleasure in presenting to 
our readers the first of a series of articles 
from Mr. Morritz Grossmann, of Saxony, the 
author of the celebrated Prize Essay on the 
Lever Escapement, and undoubtedly the most 
scientific practical horologist now living. He 
has signified several themes on which he pro- 
poses to send us communications, and we hope 
to receive one for each number of the present 
volume. We have also made him a proposi- 
tion to translate for our columns the treatise 
for which he received recently the prize offer- 
ed by the Board of Trade of Geneva, instead 
of publishing it in book form as contemplated. 

We take the following extract from Mr. 
Grossmann's letter to show some of the sub- 
jects on which he proposes to furnish commu- 
nications : 

" It is with heartfelt interest that I have 
perused your very ably edited Journal. I 
congratulate you on so good a beginning, and 
wish you the success you deserve. I wish to 
state, without flattery, that I like your Horo- 
logical Journal, as it has a decidedly scienti- 
fic tendency. 

" I have, since I read your Journal, noted 
several themes on which I propose to send 
you communications : On a new and simple 
mode of rounding wheel teeth in an epicycloi- 
dal shape ; On Remontoir escapements and 
their value; Anew Remontoir escapement for 
turret clocks ; On measuring instruments ; 
A chuck for centring flat pieces of regular 
shape (my own invention), etc., etc. 



" To make a beginning I beg you will accept 
the enclosed communication. If you should 
think it interesting, I would, at a later period, 
give the calculation of the compensating sys- 
tem, without any mathemathical formulse, 
in a plain way, accessible to all who possess 
the elements of arithmetic. If desirable, I 
am also ready to furnish the drawing of the 
pendulum." 

We also have the pleasure of introducing 
to our readers Mr. J. Herrmann, of London, 
a prominent and active member of the British 
Horological Institute, whose specialty is that 
of instructor in practical horology. We gave 
in the March No. some extracts from a lecture 
delivered by him before the British Horologi- 
cal Institute, and want of space only pre- 
vented our quoting him more extensively on 
that occasion. As he proposes to submit his 
views to the horologists of this country 
through the columns of the Journal we shall 
refrain from any comments at the present 
time, feeling assured that they will receive a 
careful consideration from our readers. 

As we stated in the outset of our course, 
the Horological Journal is intended as a 
means of intercommunication for the practical 
workmen ; and one of the leading features of 
the present volume will be practical articles 
from that source, several of which will be 
found in the present No. We are indebted 
to Mr. L. M. Bissell,of Shelburne Falls, Mass., 
for the article on the Adjustment of Balance 
Springs, translated from the French. The 
entire subject of isochronism and adjustments 
to heat and cold, and position, will receive 
especial attention in the future, giving not 
only the best foreign authorities on the sub- 
ject, but the individual experience of the best 
workmen in this country. Judging from the 
letters we have received on this subject, it is 
one in which a deep interest is felt through- 
out the country, and we invite all who have 
made it an especial study to give the result of 
their labors. 

The watch-carrying public are becoming 
more and more exacting in their demands for 
the correct performance of their time-pieces, 
and it is only by arriving at a very high degree 
of perfection in his business that a workman is 
enabled to satisfy his customers in that direc- 
tion — a fraction of a second of daily rate 
being considered of more importance than a 
minute was twenty-five years ago. 



14 



AMERICAN HOROLOGICAL JOURNAL. 



ISOCHRONAL ADJUSTMENT OF BALANCE 
SPEINGS. 



Of all the adjustments necessary in the 
parts of a good watch, the most essential to 
its performance is unquestionably that of 
isochronism of the balance spring; for if this 
adjustment is wanting, whatever may be the 
excellence of the mechanism in other respects, 
and however labored its workmanship and 
other adjustments, it will assuredly disap- 
point the expectation of the artisan, who will 
find it impossible of being regulated to pre- 
serve the same rate of going in the various 
positions in which it is liable to be placed. 

Suppose, for instance, that by comparison 
with a reliable regulator the going of a well- 
made watch is right during twelve hours in 
four vertical positions where the friction is 
greatest, and the arc of vibration of the bal- 
ance considerably diminished in extent (th.e 
positions being with the hours 12, 6, 9 and 3 
upwards during three hours each), and that 
it keeps correct time in all these positions, 
but that in the horizontal position, or with 
its face upwards, with larger arcs of vibra- 
tion, the watch gains one hundred and twenty 
seconds in twelve hours, the friction being 
lost in the horizontal positions, and conse- 
quently the arcs of vibration of greater ex- 
tent. The proper remedy in such a case is to 
make a correct isochronal adjustment of the 
balance spring. A person unacquainted with 
the adjustment would, however, fail to dis- 
cover what the true remedy would be, and 
would follow the plan usually resorted to, in 
which, by lightening the balance at the 
twelve o'clock part the times of the vibrations 
in the hanging and lying positions would be 
accommodated to each other, but not without 
increasing in the other three vertical posi- 
tions, to the great detriment of a nearly per- 
fect watch. Thus it is that many watches, 
which are fair specimens of workmanship, 
are frequently injured by false adjustments, 
and fail to preserve for their makers either 
credit or satisfaction. 

Isochronism is an inherent property of the 
balance spring, depending entirely upon the 
ratio of the spring's tension, following the 
proportion of the arcs of vibration. A balance 
spring, therefore, of any force whatever, hav- 



ing the momentum required by the law of 
isochronism, will preserve this property, 
whether it be applied to a balance having 
quick or slow vibrations; for which reason, in 
the present inquiry, every consideration is 
purposely omitted which gives to the balance 
its specific character — such as weight, diame- 
ter, etc., and it is treated simply as the balance. 

Most writers on isochronism consider the 
vibrations of the balance in its totality, and 
they have reasoned for the most part on the 
time of vibrations in their entirety; but a bet- 
ter plan would be to consider the time of 
each semi-vibration of the balance to consist 
of some number of minute equal portions of 
time, and then, by applying the known laws 
of forces to the balance, to determine what 
are the specific conditions under which the 
vibrations themselves shall in their totality 
become isochronous. The elastic force of the 
spring belongs to that class of powers called 
continuous, because the action is not by a 
single impulse, which then ceases, but by a 
number of consecutive impulses following 
each other in such rapid succession as to con- 
stitute an uninterrupted and continuous 
force, but which force is uniformly increasing 
during the bending of the spring, and uni- 
formly decreasing daring its unbending. 

The first step towards the comprehension 
of isochronism is the recognition of the ac- 
celerated and retarded motion of the balance ; 
for which purpose it must be followed, step 
by step, through the entire vibration, on the 
supposition that the time oi each semi-vibra- 
tion is divided into or composed of any con- 
venient number of equal parts — say ten. If, 
then, the balance be supposed to be moved by 
the fingers from the point where it will stand 
when at rest, over an arc of any number of 
degres, and be there held, it will be presumed 
that the spring is wound into tension, and 
acquires an amount of elastic force proportion- 
ate to the angle over which it is inflected, 
which force is then resting against the finger 
by which the balance itself is held in 
a state of rest. By the arc or angle 
of inflection of a spring is meant the arc 
passed over by the inner end of the spring, 
which is pinned into the collet ; which arc is 
always equal to that passed over by any point 
in the balance when moved from the point of 



AMERICAN HOROLOGICAL JOURNAL. 



15 



rest. The instant, however, that the finger is 
■withdrawn, the elastic force of the spring will 
be exerted in overcoming the absolute inertia 
of the balance, and at the expiration of the 
first short period of time, or one-tenth of the 
time of a semi-vibration, the spring will have 
communicated a slight motion to the balance, 
and during the second tenth the force of the 
spring is exerted against the balance in mo- 
tion, instead of at rest, as it was at the com- 
mencement of the first tenth, and will neces- 
sarily accelerate the motion that the balance 
had previously acquired, and so on during 
each succeeding tenth ; the elastic force of 
the spring continually decreasing, and con- 
stantly accelerating the motion of the balance. 
The balance having thus returned to the 
position from which it was moved by the 
finger, the first half of the vibration is fully 
completed, and a change of circumstances 
takes place. The spring which continued 
to communicate motion to the balance until 
its whole force had been transferred to it, has 
now, for an instant, resumed a state of rest. 
The balance has also assumed a new character, 
having accpiired a velocity of motion and mo- 
mentum sufficient to carry it through the 
other half of the vibration ; and in so doing to 
force the spring through an angle equal to 
that which it was originally moved through 
by the finger, and to give the spring the ne- 
cessary tension for performing the next suc- 
ceeding vibration. During the first few 
tenths of the second half of the vibration the 
spring has so little tension that its force 
retards but slightly the force of the balance ; . 
but during the succeeding tenths the tension 
gradually increases until the spring acquires 
sufficient force to entirely arrest the motion 
of the balance at the same extent of arc on 
the other side of the place of rest as that to 
which it was originally moved by the finger. 

The specific conditions under which the 
vibrations themselves, considered in their 
entirety, whether short or long, should be 
isochronous, are these : 

1st. If the time of each semi-vibration be 
conceived to be composed of the same number 
of very small equal instants of time, and 
whatever be the extent of the arc traversed, 
that the first and last of these minute instants 
of time precisely compared with the com- 



mencement and conclusion of each semi-vi- 
bration, the vibrations of such balance, 
whether long or short, will be isochronous — 
or performed in equal time. 

2d. The elastic force of the balance spring 
increases in direct proportion to the angle of 
inflection by which it is moved into tension ; 
and here it is obvious that the increasing and 
diminishing tension which causes the balance 
to follow a definite law of acceleration and 
retardation, must itself also follow a definite 
ratio of increase and decrease in order that 
the first and last of these very small equal 
instants of time shall correspond with the 
commencement and conclusion of each semi- 
vibration. 

3d. It is likewise evident that the ratio of 
change in the tension may be either one that 
proceeds too rapidly, and consequently pro- 
duces a vibration in excess, or one which 
proceeds too slowly and produces a vibration 
too short; on which account there are two 
vibrations of the spring which are not 
isochronous. 

Ath. In the former variety, producing a 
vibration in excess, the spring acquires a 
greater amount of elastic force than that 
which is due to the angle of inflection in an 
isochronal spring ; hence it follows that the 
greater the arc of vibration the greater will 
be the angles of inflection, and consequently 
the greater the excess of the undue tension. 
The effect of this undue tension will be to 
force the balance forward too rapidly during 
the first half of the vibration, causing it to 
arrive at its conclusion before the expiration 
of the time due to the isochronous vibration. 
A similar effect is produced during the second 
half of the vibration by the undue excess of 
tension accelerating the balance before the 
full number of instants of time have entirely 
expired. During each semi-vibration through- 
out the day some of these minute instants of 
time will be left unemployed, and their accu- 
mulated amount will be the amount gained in 
the long arcs of vibration, in comparison with 
the same in the short arcs. 

5th. In the latter variety the elastic force 
due to the angle of inflection will not be suffi- 
ciently great, and the spring will not have 
requisite tension to carry the balance over 
the first semi-vibration of a long arc in the 



16 



AMERICAN HOROLOGICAL JOURNAL 



time allotted to it, nor to arre&t it so soon as 
the isochronous term of the second semi-vi- 
bration requires. Each semi-vibration, there- 
fore, will occupy too large a number of 
instants in its performance, and the accumu- 
lated amount of them throughout the day 
will indicate the loss during the long arcs of 
vibration in comparison with the short arcs. 

It is evident that however great may be 
the science displayed in the inflection of the 
balance spring, it will be valueless in an 
isochronal point of view, unless it will remain 
permanently in the state in which the artisan 
leaves it. For a spring to possess this indis- 
pensable property, a high degree of perfection 
is necessarily required, demanding care in 
the selection of the material, skill in the 
manufacture, and science in the application. 
Springs are for the most part made of steel, 
hardened and tempered, though some few 
have been made of gold, of which metal cer- 
tain alloys have been particularly recom- 
mended, but their elasticity is not always to 
be relied on. The use of glass for springs 
was suggested by Berthoud, but was ultimately 
rejected. 

Balance springs must possess as perfect 
and permanent a degree of elasticity as can 
be attained ; these requisites depending upon 
the quality, hardness, and temper of the 
metal, as well as upon the form or shape of 
the spring. A soft spring gradually changes 
its form, and losing a portion of its elastic 
force, becomes unfit for use, causing the 
watch to lose on its rate. A hardened 
tempered spring, on the contrary, has a ten- 
dency to gain on its rate ; but this must not 
be considered as a defect, since it is merely 
the result of the spring having been set during 
the process of hardening, whereby it has ac- 
quiied too great a degree of rigidity. This 
rigidity, however, wears off after a few 
months' vibration in the watch, which, during 
this period almost imperceptibly gains slightly 
upon its rate, in consequence of the increased 
elastic force occasioned by the increased flex- 
ibility of the spring. When the process of 
hardening and tempering has been properly 
conducted, the gaining on its rate will be re- 
stricted within very narrow limits, and will 
entirely cease on the spring attaining its max- 
imum amount of flexibility and elastic force. 



Correctness of form or shape has been 
already stated as one of the conditions requi- 
site to insure isochronism. There are two 
forms of spring in use, viz. : the cylindrical 
or helix, and the spiral or flat spring. The 
former is exclusively used in chronometers, 
and the latter in all other kinds of watches. 
The cylindrical, which is the simplest form of 
spring, is turned in by a suitable curve to 
accommodate it to the size of the collet into 
which it is fixed, and the upper end of the 
spring is turned in by a more or less bold 
sweep, according to the indication of the 
isochronal adjustment, and is pinned into a 
fixed stud. The collet vibrating with the bal- 
ance, that point on the circumference of the 
collet, when the spring is fastened into it, 
is inflected through the same extent of arc 
as the semi-vibration consists of ; and by 
examination of the action of the spring dur- 
ing the vibration of the balance, it will be 
perceived that for each portion of the extent 
so inflected, there is a corresponding increase 
or diminution of each of the coils of the helix 
throughout the entire length of the spring, 
no part whatever being out of action. 

In order to test the isochronism of a 
spring, the chronometer must be in good 
going order. If the force of the main-spring 
be then increased by setting up the ratchet, 
the arc of vibration of the balance will be 
increased ; or, if the force of the main-spring 
be lessened by letting down the ratchet, the 
arc of vibration will be decreased, and may 
therefore be regulated to any extent desired. 
Comparisons of rate in tli2 long and short 
vibrations are then made during an equal 
number of hours in each by a good clock, 
and the difference carefully noted, which dif- 
ference indicates the state of approximation 
of the spring to isochronism, and points out 
the remedy, if it needs correction, according 
to the following rules : 

1st. If the chronometer be found to lose 
in the long arcs, it will prove that the tension 
or elastic form of the spring has not increased 
to the amount due to the angle of inflection, 
or semi-arc of vibration. Hence some 
minute portions of time are lost in each semi- 
vibration ; in the first by the balance not 
being carried forward with sufficient celerity, 
and in the second by the spring not acquiring 



AMERICAN HOROLOGICAL JOURNAL. 



17 



sufficient force to stop the balance at the iso- 
chronous point. The remedy in this case is to 
shorten the spring, thereby increasing its 
elastic force and causing its motion to become 
more rapid ; but as much time is lost by re- 
peated unpinning of the spring, the effect of 
shortening may be produced artificially, when 
the state of the isochronism is within the limits 
which experience points out, by merely 
altering the form of the upper curve so as to 
give it a greater degree of expansion. 

2d. If the chronometer should gain in the 
long arcs, in comparison to the time it keeps 
when vibrating in short arcs, it proves that 
the tension increases in a ratio beyond that 
which is due to the angle of inflection. In 
this case, if it keeps time when the semi- 
arc of vibration is one hundred degrees, it 
will gain when it vibrates two hundred 
degrees; for, instead of having as much force 
as would compel the balance to vibrate over 
double the space with double the mean velo- 
city, which would of course occupy the same 
time, it will possess an excess of tension 
which will increase the velocity of each semi- 
vibration, and necessarily shorten the time 
of performing them ; causing an accumula- 
tion of instants, which will be the gain per 
diem. The remedy for such a spring is to 
increase the length of the part in action; but 
this is not always convenient or possible in 
the isochronal adjustment; but an expedient 
is resorted to in which an artificial length 
is given to the spring by compressing the 
curve of the part bent inwards at the upper 
end so as to make the curve commence its 
inward direction at a point a little farther 
distant from the stud. Before attempting t 
make any alteration in a spring, it is advisable 
to examine the state of the curves, more 
especially when the chronometer gains in the 
long arcs, as it will sometimes be found that 
one of the curves is turned abruptly, which 
has the effect of causing a gain in the long 
arcs in consequence of the spring abutting so 
directly against the curve as to leave a part 
of its length in very imperfect action. The 
opinion of early writers on the subject was, 
that in a certain determinate length of wire 
there are several isochronal points, to either 
of which a balance may be adapted, accord- 
ing to the motion of the vibrations it is in- 



tended to perform. Suppose, for instance, 
that a cylindrical spring, having ten turns, 
be found isochronal ; one of these turns (or 
more) may be taken away, and a point in the 
spring still be found that will give the required 
ratio of increasing tension, and produce 
isochronal vibration. 

The spiral or flat spring is less simple in its 
form than the cylindrical, and although, what- 
ever may be its form, the principles upon 
which its isochronism depends are not altered, 
yet there are circumstances which affect its 
isochronal perfection in so marked a degree 
that this requires to be particularly noted ; 
and the more especially so since the spiral 
springs are more commonly employed than 
the cylindrical, and their construction in- 
volves several points of greater nicety in their 
manipulation. The proper length and strength 
of wire having been selected, the manner in 
which it is turned up into a spiral is impor- 
tant, for in this operation its natural isochro- 
nism may be either partially or wholly de- 
stroyed. This will surely be the case if there 
be any small points or elbows in it, or if the 
spring be so made that during the vibration 
any part thereof be either inactive or have an 
imperfect action. Indeed, the absolute ne- 
cessity for the spring to continue in free and 
unrestrained action throughout its entire 
length, and during the whole period of the 
vibration, cannot be too strongly urged, be- 
cause an opinion generally prevails that the 
outer turns do not come into action until 
near the end of the semi-vibration. With a 
cylindrical spring there is no difficulty in pro- 
ducing the same extent of vibration on either 
side of the point of rest. With a flat spring, 
however, this is not obtained with an equal 
degree of facility, nor without the closest 
attention to its form, as well as to the pinning 
it in, so that it shall not in the slightest de- 
gree depart from its natural shape when out 
of the watch. 

A spiral spring, to be turned up correctly, 
should lie in several close turns towards the 
centre, springing off into a gentle curve when 
it is pinned into the collet, and then gradu- 
ally and constantly expanding in such a man- 
ner that each part of the spiral would cross, 
but nowhere coincide with, a small circular 
arc drawn from the centre of the collet and 



18 



AMERICAN HOROLOGICAL JOURNAL. 



concentric thereto. This is perfectly indis- 
pensable to isochronisrn. If, on the contrary, 
a spiral springs off from the collet, first by a 
large bold sweep, and then lies in a few close 
and large turns, it will be very defective in its 
action, and quite devoid of the isochronal 
property. In such a spring the middle of the 
vibrations will not coincide with the point of 
rest, for the spring will yield readily to the 
momentum of the balance during the wind- 
ing up of its coils, and the whole length of 
the spring will be brought into action, though 
imperfectly ; but during the expansion of the 
coils, upon the return of the balance, the ac- 
tion of the inner turn will not be exerted 
against curves which lie across concentric 
circles, but such as lie in concentric circles, 
or nearly so, and will therefore abut so point 
blank against them as to cause no displace- 
ment whatever in a portion of the outer turns, 
thus giving the effect of a short strong spring, 
which arrests the balance too soon in this 
part of the vibration. Such irregularities are 
obviously incompatible with the requisites for 
producing isochronal vibrations. 

The isochronal trial of a flat spring in a 
watch is more simple than that described for 
a chronometer, since the balance of a watch 
is thrown into the long or short arcs of vibra- 
tion by a mere change of position, which 
changes the amount of friction, and conse- 
quently the extent of arc. In the horizontal 
position, with the dial uppermost, the friction 
is least, and the vibrations of the fullest ex- 
tent ; in the vertical, or th&position in which 
the watch is worn, the friction is greatest, and 
the extent of the vibration necessarily cur- 
tailed. The trial is made by the aid of a good 
clock, by comparing the rate of running 
during a certain number of hours in a hori- 
zontal position, with the mean result of an 
equal number of hours running in any two 
opposite vertical positions. For instance, 
first with the 12 and then with the 6 
upward ; and then in like manner with the 
9 and the 3 upward ; the mean result 
of two opposite vertical positions being re- 
quired in order to neutralize any slight 
irregularities that may exist in the poise of 
the balance. The indication and the applica- 
tion of the isochronal adjustment are the same 
as those already described for the cylindrical 



spring, but under greater restrictions. For, 
as the balances for watches are, for the most 
part, unprovided with any means by which 
their inertia may be varied, as is done in the 
compensation balance, so as to suit the elastic 
force of any particular spring and the num- 
ber of vibrations required to be performed in 
a given time, the spring must not only be 
isochronal, but of the precise degree of elas- 
tic force demanded by the particular balance 
to be employed. The selection of a spring 
in this case, within the limits of isochronal 
adjustment, must be made by trial in the 
watch. 

The great advantage of an isochronal 
spring is its innate power of resisting the 
influences which cause any change of ratio — 
such as change of position, increased friction 
as the watch becomes dirty, or the viscidity 
of the oil in low temperatures. It is sur- 
prising to see chronometers return from sea 
with scarcely a change of rate, although they 
have been going for three or four years, and 
even longer periods of time, and the vibra- 
tions had fallen off to a very small arc in con- 
sequence of the oil becoming so viscid that 
in some instances a slight degree of force 
has been found necessary to draw the pivot out 
of the fourth hole. But what is still more 
remarkable, some of these chronometers, after 
having been cleaned, have been known to 
take up their original rate, although with, 
perhaps, threefold vibration. 

The method by which an isochronal spring 
arrives at such perfection may be thus ex- 
plained : The spring's elastic force is pre- 
supposed to be both perfect and permanent 
under similar temperatures ; for, as has been 
previously stated, the elastic force diminishes 
as the temperature to which it is exposed is 
increased. The elastic force of the spring is 
counterbalanced by the resistance it meets 
with in the work it has to perform, which is 
of two kinds — the inertia of the balance, and 
the friction of the rubbing parts, to which all 
machinery is more or less subject. If the 
spring is assumed to possess a force equal to 
100, and that 10 of those parts are requisite 
to overcome the friction when at a minimum, 
there will be 90 parts left for action upon the 
balance. But the friction wiU vary accord- 
ing to circumstances, although the spring and 



AMERICAN HOROLOGICAL JOURNAL. 



19 



balance remain unaltered. If, therefore, the 
spring has power to carry the balance through 
a certain arc of vibration "when the friction is 
at a minimum, it will have the power to per- 
form the same amount of work when the 
friction is at a maximum, but the 100 parts of 
power will be differently proportioned in the 
execution of the work. Let it be assumed, 
for instance, that the friction is trebled ; then 
will there be 30 parts expended in overcom- 
ing the friction, and consequently 70 parts 
only left for action upon the balance, which 
will necessarily have less extent of vibration. 
Now, since the isochronal ratio of the spring's 
tension remains unaltered, the commencement 
and end of every semi-vibration will coincide 
with the first and last of the minute instants 
of time comprising the isochronous vibration, 
which is the condition required for correct 
performance. 

So it is, also, with increased friction ; the 
elastic force of the balance spring being con- 
stantly proportional to the angle of inflection, 
whatever may be the amount of friction, the 
law of isochronism remains unimpaired, and 
friction is only an adventitious circumstance, 
which affects the extent of the arc of vibra- 
tion, but not the time in which it will be de- 
scribed. 



CALCULATION OF WHEEL TEETH. 

The books written on this subject are all 
more or less so complicated as to almost en- 
tirely exclude them from the understanding 
of the general repairer. This arises from 
the fact that their problems and solutions are 
generally carried out in algebra— a study, 
unfortunately, that very few repairers are 
conversant with, as I have proved to my sat- 
isfaction by actual observation. Such being 
the case, and believing that a plain practical 
treatise on this subject was desirable, I have 
endeavored in the following article to give 
rules combining simplicity and precision, 
and so arranging them that any one with a 
knowledge of the first four rules in arith- 
metic can easily comprehend and apply 
them. 

Query. — How many revolutions will the last 
wheel or pinion in a train make for one turn 



of the first wheel, the number of wheel and 
pinion teeth being given ? 

Bide. — With the product of all the working 
pinion leaves multiplied together, divide the 
product of all the working wheel teeth multi- 
plied together, and the quotient will be the 
number of turns and part of turns the last 
wheel or pinion will make for one of the 
first. 

Problem. — Suppose the wheel teeth thus: 
100, 80, 60, 50, and the pinions 20, 16, 10, 8. 
The operation would be 

100 X «0 X 60X50 24000000 

20 X 16 X 10 X 8 " : 25600 ~~ 937 *' 

this number being the turns of the last wheel 
in this train, for one of the first wheel. The 
desired result may also be obtained by divi- 
ding each wheel by its working pinion sepa- 
rately, and multiplying all the quotients to- 
gether, thus: 

W—B; H=5; fS=.6; V-=6|; 5X5X6 
X6J = 937|. 

Problem Second. — Given the number of beats 
in an hour, the number of wheel and pinion 
teeth ; required the number of teeth to give 
the escape wheel so as to obtain the given 
number of beats an hour. (The balance makes 
two beats, in most escapements, for every tooth 
in the escape wheel ; therefore, if the latter 
have 20 teeth, the balance would make 40 
vibrations for every revolution of the escape 
wheel; if the escape wheel have 15 teeth, then 
30 vibrations, etc.) 

Pule. — Divide one-half the number of given 
beats in an hour by the number of turns of the 
escape wheel or pinion for one of the centre 
wheel, and the quotient will be the proper 
number of teeth to give the escape wheel. 

Example. — Suppose the number of beats in 
an hour to be 16,800, and the number of wheel 
teeth and pinion leaves to stand thus : 
wheels 80, 60, 56 ; pinions 8, 8, 7 ; by the 
preceding rule we find the turns of the es- 
cape wheel or pinion for one of the centre 
wheel to be 600. The number of beats in an 
hour being 16,800, the half of this would be 
8,400, and this divided by 600 will give 14— 
the proper number of teeth for the escape 
wheel. 

Problem Third. — How many hours a watch 
or clock will run before being again wound up, 



20 



AMERICAN HOROLOGICAL JOURNAL. 



the number of teeth in the barrel, and the 
number of turns it can make before the spring 
runs down, together with the number of the 
centre pinion teeth, being given. 

Rule. — Divide the number of barrel teeth 
by the number of centre pinion teeth, multi- 
ply the quotient by the number of turns the 
barrel can make, and the product will be the 
number of hours the watch will go before 
being again wound up. 

Example. — Suppose the barrel to have 96 
teeth, the centre pinion 8, and the number of 
turns the barrel can make to be 3 ; 96 divi- 
ded by 8 gives 12 — the number of turns (or 
hours) the centre pinion makes for one of the 
barrel, which multiplied by 3, the number of 
turns the barrel can make, will give 12X3= 
36 — the number of hours it will go without 
again winding. If it be desired to have the 
watch go 30 hours, and the number of turns 
of the barrel to be 3, the barrel would then 
have to make 1 turn in 10 hours, and conse- 
quently must have ten times as many teeth 
as the centre pinion. If we choose to have 
8 teeth for the centre pinion, the barrel must 
then have 10X8=80 ; if 6 teeth, then 6X10 
=60, etc., etc. When the watch or clock is 
desired to go a longer time, 8 days for in- 
stance, it is necessary to have an additional 
wheel and pinion, placed between the barrel 
and centre wheel. "VVe will suppose the bar- 
rel to have 96 teeth, the additional wheel to 
have 80, its pinion 12, and the centre wheel 
pinion 10 ; it will be seen that the additional 
wheel makes but one turn in 8 hours, as f-{7=8, 
and the barrel only one turn in f f X 8 = 64 
hours, so that the watch or clock, with 3| 
turns of the barrel, will go 8 days. On the 
same principle it may be made to go a month 
or a year by adding one or more wheels. 

Problem Fourth. — What number of teeth 
to give the wheels in a train consisting of 
wheels and pinions so that the last wheel or 
pinion numbers a given number of turns for 
one turn of the first wheel. 

Rale. — The number of teeth in the pinions 
must first be chosen and fixed upon, these 
numbers multiplied together, and with this 
product multiply the number of turns the 
last wheel is to make ; this will give such a 
number that, when divided by single factors, 
as 2, 3, 5, 7, etc., until the product (continuing 



each prime number until it no more equally 
divides) will give such prime numbers that 
can be multipled together in sets to suit. 

Example. — We will choose the number of 
pinions 12, 10, 8, and the number of turns 
the last wheel is to make (for one of the first) 
200 ; these numbers multiplied together give 
12X10X8X200=192,000 ; this divided by 
prime numbers gives 192000-h2=96000-f-2 
= 48000-^2=24000-f-2=12000-f- 2=6000^- 2 
=3000-^-2=1500-^2= 750-^2=375-^3=125 
-^-5=25-f-5=5-f-5=l ; these factors are now 
multiplied together to suit, in the following 
manner: 5X5X^X2=150, for the first wheel; 
5X2X2X2=40, for the second ; and 2X2X 
2X2X2=32, for the third wheel, as the fol- 
lowing proof will show : 1 T \°=12|, y£=4, ^ 
=4, and these quotients multiplied together 
give 12^X4X4=200. If these numbers are 
thought not fitting on account of the size of 
the wheels, they can be arranged differently, 
thus : 5X2X 2 X2X2=30 ; 5X3X2X 2 =60; 
5X2X2X2=40. 

Proof.— -f§=6f, .<4>=6,Y=5 ; these multi- 
plied together give 6§X6X 5=200, showing 
the numbers to be proper. 

Problem Fifth. —What number of teeth to 
give to the wheels in a train consisting of 3 
wheels and pinions, when the balance is to 
make 16,800 vibrations an hour, or in the 
time the minute-hand makes one turn, and 
the escape wheel has 14 teeth. 

Rule. — Divide the number of beats in an 
hour by double the number of the escape 
wheel teeth. This quotient will be the num- 
ber of turns the escape wheel will make in 
an hour ; the numbers for the pinions are 
then chosen, multiplied together, and with 
the product multiply the former number of 
turns the escape wheel makes in an hour ; 
this product is then divided by prime num- 
bers, and multiplied together into sets to 
suit. 

Example. — 16,800 being the number of 
beats given in an hour in the above problem, 
this, when divided by 28, double the number 
of escape wheel teeth, gives 600 — the num- 
ber of turns the escape wheel will make in 
an hour. The pinions are then chosen, 
which, in this case, will be 3 pinions of 8 ; 
these multiplied together, and then with the 
number of turns the escape wheel makes in 



AMEKICAN HOROLOGICAL JOURNAL. 



21 



an hour, gives 8X8X8X600=307200 ; this, 
divided by prime numbers, shows them to be 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 5, 5, which 
can be arranged into the following sets : 5X 
2X 2X 2X 2=80 ; 2X 2X 2X2X2X2=64 ; 
5X3X2X2=60 — numbers very good for 
practical use. 

Problem Sixth. — "What number to give to 
the teeth of wheels in a watch where the 
seconds hand makes one turn in a minute, or 
GO turns in the time the balance makes a 
given number of beats in an hour. 

Note. — The fourth, or seconds wheel must 
always make 60 turns for one of the minute, 
or centre wheel. 

Bide. — The train is divided by 60, which 
will give the number of beats in a minute, 
and this quotient is then divided by double 
the number of escape wheel teeth, which will 
give the number of turns the escape wheel 
will make in a minute ; from this quotient is 
derived the number of teeth for the seconds 
wheel and the escape wheel pinion. If the 
quotient is composed of a whole number, 
then the escape wheel pinion may be any 
number chosen ; the seconds wheel must then 
have as many teeth as the product of the quo- 
tient multiplied by the number chosen for the 
escape wheel pinion ; but should the quotient 
be a number with a fraction attached, then 
the number must be altered into an improper 
fraction — the denominator of which will be 
the number for the pinion, and the numerator 
the number for the seconds wheel. If the 
improper fraction be thought too high it may 
be reduced. 

Example. — Suppose the number of beats in 
an hour to be 18,000, and the escape wheel to 
have 15 teeth ; 18,000 divided by 60 gives 300 
beats a minute ; this quotient being divided 
by 30, double the number of escape wheel 
teeth, gives 10 ; this being a whole number, 
the escape wheel pinion may be of any num- 
ber. If we choose 8 for the pinion, the seconds 
wheel must have 8X10=30 ; if 6, then 
6X10=60. 

Example. — The beats an hour 18,000, the 
escape wheel 14, what must be the number of 
teeth for the seconds wheel and escape wheel 
pinion ? u$a o=300 ; this divided by 28, 
double the number of escape v>heel teeth, 
gives W=10ffc or 10$ ; this altered into an 



improper fraction, gives ^-, being 7 for the 
escape wheel pinion, and 75 for the second 
wheel. 

The calculation of wheel teeth in planeta- 
riums is far more complicated, but as this is 
not in the line of repairs we will not enter 
upon it. The preceding rules and examples 
are so arranged that the first three rules may 
be applied to any clock machinery ; the last 
three being designed especially for watch- 
makers. 

Charles Spiro. 

212 Broadway, N. Y. 



DIALING. 



NUMBER ONE. 



" W; t ih the dial's shadow moving, 
Life and Time are worth improving ; 
Seize the moments, while they stay ; 

Seize and use them, 

Lest you lose them, 
And lament the wasted day." 

Dialing, or " G-nomonics," as it is some- 
times called, has found its foundation in the 
astronomical theory of the sun's motions, and 
very naturally grew out of the observed mo- 
tion of the shadows cast by its apparent daily 
rotation. 

The earliest mention made of a dial is 
found in the Bible. " In those days Hezekiah 
was sick to the death, and prayed unto the 
Lord, and He spake unto him, and He gave 
him a sign." Chap, xxxii., v. 34, 2d Chronicles. 
" Behold I will bring again the shadow of the 
degrees, which is gone down in the sundial 
of Ahaz, ten degrees backward ; so the sun 
returned ten degrees by which degrees it was 
gone down." Chap, xxxviii. Isaiah. 

The earliest knowledge we have for a cer- 
tainty, was the " Hemicyle," or concave hemi- 
spherical dial of the Chaldean astronomer, 
Borosus, 540 years before Christ. It was a 
very natural construction, being a concave 
hemisphere, with a small sphere or ball sup- 
ported in the centre of the horizontal plane 
of the hemisphere. At sunrise or sunset, no 
shadow would be cast on the inner surface, 
but as the sun's altitude increased, the shadow 
was. projected on the concave of the hemi- 
sphere. This construction of Borosus de- 



22 



AMERICAN HOROLOGICAL JOURNAL. 



scended beyond the time of Hipparchus and 
Ptolemy, and was found in use among the 
Arabians in the year 900. Four of these an- 
cient dials have been recovered in Italy. One 
in the year 1746, at Tivoli, supposed to have 
belonged to Cicero, who mentions having sent 
such a one to his villa near Tusculum. The 
second and third were found in 1751; one at 
Castel Nuovo, the other at Rignano, and a 
fourth at Pompeii in the year 1762. This 
latter differs from the others in that the trop- 
ics are not expressly on it, the equator only 
being seen. It seems a little strange that no 
dials are found among the Egyptian antiqui- 
ties ; there is nothing of the kind delineated 
in any of their sculptures or frescos. Some 
have supposed that the numerous Obelisks 
found everywhere in Egypt, were erected in 
honor of the sun, and were used as huge 
" gnomons," whose shadows served to make 
apparent the divisions of the day. But it 
seems hardly probable that such enormous 
dials should be in use, and none smaller, and 
far more convenient, be found or heard of 
among that learned people. 

The subject of dialing was greatly agitated 
during the 17th century by all the writers on 
astronomy. The 18th century produced some 
writings on the subject, but clocks and 
watches had, by this time, begun to super- 
sede the use of dials, and the art of construct- 
ing them was pursued mostly as a mathe- 
matical recreation. 

The subject of dialing was suggested to 
the mind of the writer by the very excellent 
series of papers in the Journal on " Astron- 
omy in its Relations to Horology,'' and that 
a comparison between the earlier and ruder 
modes of the ancients, and our present per- 
fected science and instruments, would not be 
out of place. We do not propose to go into 
the purely scientific aspect of the subject, for 
it would be far more curious than useful, and 
to be fully comprehended, would require a 
complete knowledge of geometry, plane and 
spherical trigonometry — in fact, the highest 
mathematical education. It would be of no 
utility or interest to the astronomer, having 
been superseded by modern advancements ; 
and to the generality of artisans it would be 
dry and incomprehensible for want of the 
requisite mathematical education. 



The Horologucal Journal being professedly 
practical, devoted not so much to philosophy 
as to fact, we shall give only in the future arti- 
cles such plain, arbitrary directions for the 
construction of various descriptions of dials, 
as will enable the uneducated to construct 
them correctly, for their own use or amuse- 
ment, and perhaps thereby stimulating some 
of the younger members of the craft to aspire 
to a more thorough knowledge of astronomi- 
cal science, as connected with their chosen 
occupation, and to seek for the reason " why 
these things are thus." 

The apparent diurnal motion of the " starry 
heavens " is perfectly uniform. The sun's 
apparent diurnal motion about the earth's 
axis, however, deviates a little from perfect 
equality by its unequal angular motion in the 
ecliptic, and its obliquity to the equator. 
These inequalities need not be attended to in 
the construction of a dial ; their joint effect 
is compensated for by the " equation of time," 
a correction which must always be applied 
to the time it indicates, which table of equa- 
tion is every month furnished correctly by 
the Horological Journal, on its last page. 
The refraction of light might also be taken 
into account, but its error being less than 
that of construction {which is entirely a 
graphical operation, subject to the imperfec- 
tion of instruments), it may be neglected. 
The time, as indicated by a dial, is suffi- 
ciently accurate for the ordinary affairs of 
life. But its error, whatever it may be, un- 
like that of a clock, is not carried forward 
day after day — it remains constantly the 
same ; if it be one minute a day, it is only a 
minute out of truth, but the incorrect clock 
is one minute to-day, two minutes to-morrow, 
three minutes next day, and so on ; and in a 
week, or at farthest a month, has gone so far 
wrong as to be wholly unreliable, until reset 
to the correct time. 

All the knowledge that will be required, is 
ordinary education, and to know how to 
draw parallel lines and perpendiculars, and 
to measure angles ; and all the instruments 
necessary are compasses, a scale of chords 
(the construction of which will be shown), or 
a protractor, for the measurement of angles, 
and a straight edge rule. 

Still, we cannot enter upon these instructions 



AMERICAN HOROLOGICAL JOURNAL. 



23 



without expressing the hope that every young 
mechanic will at once, if he has not already, 
make himself more or less familiar with 
geometry: even a little knowledge of that kind 
will be found useful every day, and the time 
spent in its acquirement will never be 
regretted. 

o 

METHOD OF DETERMINING DISTANCES. 



I send you a table for finding the differ- 
ence of time between two places, knowing the 
distance between the meridians passing 
through them, in statute miles. It was sug- 
gested by the table on page 327 of No. 11 
of Horological Journal, giving the latitude 
and longitude of different places in the 
United States. 

Table showing the Distance, in Statute Miles, on any Lati- 
tude from 20° to 50°, inclusive, corresponding to 1 Minute 
of Time, and also for 1 Second of Time. 





Distance 


Distance 




Distance 


Distance 


Lat. 


for 


for 


Lat. 


for 


for 




1 Min. 


lSec. 




1 Min. 


1 Sec. 


20° 


16 25 


.271 


36° 


14 00 


.233 


21 


16.15 


.269 


37 


13.82 


.230 


22 


16.01 


.267 


38 


13.64 


.227 


23 


15.92 


.265 


39 


13.45 


.224 


24 


15.80 


.2o3 


40 


13.26 


.221 


25 


15 68 


.261 


41 


13.07 


.219 


26 


15 55 


.259 


42 


12 87 


.215 


27 


15 41 


.257 


43 


12 66 


.211 


28 


15.27 


.255 


44 


12 46 


.207 


29 


15 13 


.252 


45 


12 24 


.204 


30 


14 98 


.249 


46 


12.03 


.200 


31 


14 83 


.247 


47 


11 81 


.197 


32 


14.67 


.244 


48 


11 59 


.193 


33 


14.51 


.242 


49 


11 36 


.189 


31 


14.18 


.236 


50 


11.13 


.185 


35 


14.18 


.236 









This table gives the distance on any parallel 
of latitude from 20° to 50° inclusive, corre- 
sponding to one minute of time, and also to 
one second of time. This distance divided 
into the distance between the meridians of 
two places, will give the difference of time 
between those two places in minutes and 
seconds. It is computed from one adopted 
by U. S. Topographical Engineers, showing 
the length of a degree of longitude, in statute 
miles, on any parallel of latitude, and which 
also takes into consideration the oblateness 
of the earth. 

I cannot, perhaps, explain the table better 
than by giving an example requiring its use. 



Given the distance between the meridians 
of Ann Arbor and Grand Rapids, Michigan, 
as counted by the ranges of townships on 
latitude 43°=98 miles; required the differ- 
ence of time of those two places. Looking 
into the table, I find the distance for one 
minute on latitude 43°, is 12.66 miles ; this 
divided into 98 gives 7 minutes, and a 
remainder of 9.38 miles. This remainder 
divided by the distance for one second en the 
same latitude, viz. : .211 miles, gives 44 
seconds, so that the difference of time is 7 
minutes 44 seconds. 

Again, the distance between the meridians 
passing through Ann Arbor and Chicago, is 
between 197 and 198 miles, as counted by 
the township ranges (a range being six 
miles), — say 197.5 miles. Required the dif- 
ference of time between Ann Arbor and 
Chicago, the distance between the meridians 
being counted near the parallel of 42°. 

Looking into the table, I find that on lati- 
tude 42°, the distance for one minute is 
12.87 miles, and for one second, .215 miles, 
and 197.5 divided by 12.87 = 15 minutes, 
with a remainder of 4.45 miles ; this remain- 
der divided by .215, the distance due to one 
second = 20 seconds, and the required dif- 
ference of time is 15 minutes 20 seconds, 
which varies only about one second from the 
time due to difference of longitude of those 
two places, as given by the table of longitudes 
referred to in No. 11 of the Horological 
Journal. 

It is to be observed that the distance 
between two meridians may be measured on 
any latitude, but the distance taken from the 
table for a divisor must be from the same lati- 
tude. 

In the same manner, and with the help of 
the table referred to in No. 11 of the Horo- 
logical Journal, giving the latitude and 
longitude of different places in the United 
States, the difference of time, and conse- 
quently the difference of longitude of any 
two places in this vast territory, may be deter- 
mined to a few seconds of time. Indeed, in 
the Western States, where the domain is sur- 
veyed into six-mile townships, the difference 
of time between any two places within a 
moderate distance of each other, may be 
known to a second. 



24 



AMERICAN HOROLOGICAL JOURNAL. 



In Great Britain, local time is ignored, or 
rather the time of one place, by common 
consent, is regarded as the time of any other 
place on the island — the great clock of 
Westminster ticking the time by telegraph 
to every town of the kingdom. Not so in 
America, which embraces more than 3| hours 
of longitude. 

H. C. Pearsons. 

Ferrysbtjrg, Mich., 

JKS " Answers to correspondents, as well as 
other interesting articles, are unavoidably 
crowded out in this number, but will be 
attended to next month. 



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EQUATION OF TIME TABLE. 

GREENWICH MEAN TIME. 

For July, 1870. 



ii 




Sidereal 










© 




Time 


Equation 


Equation 




Sidereal 


0> 


Day 


of 

the Semi- 


of 
Time to be 


of 
Time to he 


Difif. 


Time 
or 


— 




diameter 


Added to 


Subtracted 


One 


Right 






Passing 


Apparent 


from 


Hour. 


Ascension 






the 


Time. 


Mean Time. 




of 


n 




Meridian. 








Mean Sun. 






s. 


M s. 


M. s. 


s. 


H. M. s. 


Fri 


1 


68.79 


3 29.63 


3 29.60 


0.486 


6 37 20.84 


Bat 


2 


68 75 


3 41.19 


3 41.16 


0.475 


6 41 17.40 


Rn. 


3 


68 71 


3 52.46 


3 52.43 


0.462 


6 45 13.96 


M.. 


4 


68 67 


4 3.42 


4 3.39 


0.448 


6 49 10.51 


Tu. 


5 


68.63 


4 14.06 


4 14.03 


0.434 


6 53 7.06 


W 


6 


68.58 


4 24.33 


4 24.30 


0.419 


6 57 3.62 


Th. 


7 


68.53 


4 34 23 


4 34.20 


0.403 


7 1 0.18 


Fri. 


8 


68 48 


4 43.74 


4 43.71 


0.386 


7 4 56.74 


Sat 


9 


68.42 


4 52.84 


4 52 81 


0.369 


7 8 53.29 


So. 


10 


68. 3 '5 


5 1 51 


5 1.48 


0.351 


7 12 49.85 


M.. 


11 


68.30 


5 9.75 


5 9.72 


0.333 


7 16 46.41 


Tu. 


12 


68.24 


5 17.54 


5 17 51 


0.314 


7 20 42.97 


W. 


13 


68 17 


5 24.86 


5 24 83 


0.295 


7 24 39.53 


Th. 


14 


68 10 


5 31.71 


5 31.69 


0.275 


7 28 36.08 


Fri. 


15 


68.03 


5 38 08 


5 38.06 


0.255 


7 32 32.64 


Sat 


16 


67 96 


5 43.98 


5 43 95 


0.235 


7 36 29.20 


Su. 


17 


67.88 


5 49 37 


5 49 35 


0.214 


7 40 25.75 


M.. 


18 


67.81 


5 54.24 


5 54.22 


0.193 


7 44 22.31 


Tu. 


19 


67 73 


5 58.61 


5 58.59 


0.171 


7 48 18.86 


W. 


20 


67 65 


6 2.45 


6 2 43 


0.149 


7 52 15.42 


Th 


21 


67.57 


6 5.76 


6 5.74 


126 


7 56 11.98 


Fri 


22 


67'. 49 


6 8.53 


6 8.51 


0.103 


8 8.53 


Sat 


23 


67.41 


6 10 74 


6 10 72 


0.080 


8 4 5.08 


Su. 


24 


67.33 


6 12 37 


6 12./56 


0.056 


8 8 1.64 


M.. 


25 


67 25 


6 13.43 


6 13.43 


0.032 


8 11 58.20 


Tu. 


26 


67 17 


6 13 92 


6 13.92 


0.008 


8 15 54.76 


W. 


27 


67.08 


6 13 8 ! 


6 13.84 


0.017 


8 19 51.31 


Th. 


28 


67 00 


6 13.14 


6 13.15 


0.041 


8 23 47.87 


Fri 


29 


66.91 


6 11.85 


6 11.86 


0.066 


8 27 44.43 


Sat 


30 


66 82 


6 9.97 


6 9 98 


0.091 


8 31 40.98 


Su. 


31 | 


66.73 


6 7.46 


6 7.47 


0.117 


8 35 37.54 



Mean time of the Semidiameter passing may be found by sub- 
trading 0.19 s. from the sidereal time. 

The Semidiameter for mean neon may be assumed the same a s 
that for apparent noon. 



PHASES OF THE MOON 



D. H. M. 



) FirstQuarter 5 16 30.4 

© Full Moon 12 10 35.5 

{ Last Quarter 20 2 17.1 

© New Moon 27 23 18 

D. H. 

i Perigee 8 14.9 

i Apogee 20 18 

O / ;; 

Latitude of Harvard Observatory 42 22 48 1 

H. M. S. 

Long. Harvard Observatory 4 44 29 . 05 

New York City Hall 4 56 0.15 

Savannah Exchange 5 24 20 572 

Hudson,Ohio 5 25 43.20 

Cincinnati Observatory 5 37 58.062 

Point Conception 8 142.64 

APPARENT APPARENT MERID. 

R. ASCENSION. DECLINATION. PASSAGE. 

D. H. M. S. , „ H. M. 

Venus 1 3 55 7.65.. . .-18 12 0.2 2118.5 

Jupiter.... 1 4 43 17. 66.... +21 41 9.4 22 3.2 

Saturn... 1 17 34 51.29.. .. -22 4 52.3 10 55.6 



AMERICAN 



Horolosdcal 




Vol. H. 



NEW YORK, AUGUST, 1870 



No. 2. 



CONTENTS. 
Chronometer Escapement, ........ 25 

Me. Grossmann's Pendulum Analyzed, ... 31 

Heat, . . 34 

The Comeng Workmen, 36 

Isochronism 39 

Dialing, 40 

"Watch and Clock Oil, 43 

Soft Solder, 44 

Watch Cleaning, 45 

Answers to Correspondents, 46 

Equation of Time Table, 48 

* * * Address all communications for Horological 
Jocknal to G. B. Mellek, P. 0. Box 6715, Xew York 
City. Publication Office 229 Broadway, Room 19. 

THE CHRONOMETER ESCAPEMENT; 



Much as it is worthy of a more extensive 
treatise than can be entered upon within the 
limits of an article like the present, and much 
as it deserves the attention of an abler pen 
than that of the writer's, yet, a great deal in 
favor of the above escapement need not be 
said to advocate its superior worth, for no 
one who is in a measure acquainted with ho- 
rology will deny that, for accuracy of time- 
keeping it is the most valuable one; for wher- 
ever important operations of both scientific 
and practical nature depend on the exact 
measurement of time, it has proved most ser- 
viceable. There is, however, a class of chro- 
nometers whose performance as timekeepers 
has not proved worthy of this claim, and in a 
previous article on this subject the writer has 
endeavored to show in a measure the reason 
why and the consequences thereof ; there 
being an opinion, at least, among the unini- 
tiated ones, that the chronometer escapement 
is not as reliable for pocket use as others, or, 
as it proves to be, for stationary purposes ; 
this, it was said, might be tested, and the 
reputation of the good chronometer vindica- 
te, and in this behalf the following is respect- 
fully submitted : 

A thorough analysis of the principles of the 



escapement, as compared with others, would 
probably furnish the most conclusive evidence 
in its favor, and would at the same time be 
most instructive to the student ; but as this 
would involve too much time and space, and 
as otherwise the superiority of the escape- 
ment is already admitted, the writer claims 
that, if this existing opinion is proved to be 
erroneous and invalid, the object is attained. 
It is said by those who hold this opinion, that 
the chronometer escapement is apt to set 
when being carried. This could result from 
no other cause than from external motion, as 
affecting the vibrations of the balance. As is 
known, it is not the nature of the escapement 
to start of itself when the vibrations of the 
balance are stopped, but the latter requires to 
be moved through an arc of from 12° to 16° 
before it will unlock and receive the first im- 
pulse; hence it is supposed possible for ex- 
ternal motion to counteract the vibrations so 
as to check them below the amount of motion 
required to unlock again, and in that case the 
watch would stop. Now we may be able to 
form an idea of the possibility of such an oc- 
currence in the following way: In an escape- 
ment where the locking takes place at the 
second tooth from the roller, the balance re- 
quires to be moved through an arc of 12° to 
effect an unlocking. Assuming the vibra- 
tions of the balance to be 18,000 in an hour, 
hence 5 in a second, and supposing them to 
describe arcs of 400°, and the external motion 
of the watch during ^ of a second, the time of 
one vibration, to be 80° of arc, it follows that 
the motion of the balance is five times swifter 
than the external motion of the watch; hence 
the arcs of vibration of the former could only 
be increased or decreased (according to the 
direction in which the watch were moved) by 
-i — that is, increased to 480°, and in the con- 
trary effect decreased to 320°. Again, if we 
suppose the external motion of the watch to be 
three times as much, thus to describe an arc of 



26 



AMERICAN HOROLOGICAL JOURNAL. 



240° during the time of one vibration of the 
balance, its velocity would still be If as great 
as such external motion, and its arcs of vi- 
bration could not be increased above 640°, 
nor decreased below 160°. To effect two suc- 
cessive unlockings during one vibration of the 
balance it would require an increase of the 
arcs to 720°, and to check it entirely, so as 
to stop the watch, the latter would have to be 
moved through an arc nearly equal in extent 
to the arcs of vibrations, and in the same 
time in which one of them is completed. 
Now it must be remembered that only such 
external motions of the watch could influence 
the vibrations of the balance as describe 
circles, and very small ones too, for the larger 
the circle of arc the nearer would it be in a 
straight line ; and if a watch were moved in 
a straght line, however swift such motion 
might be, it could not have any influence on 
the vibrations of the balance, for th eeffect 
of such motion on one side of the line would 
be counteracted by the effect of the same 
motion on the other side of the line ; and 
hence the idea entertained by so many work- 
men, that the simple act of taking a watch 
out of the pocket and putting it back again 
is sometimes sufficient to stop it, may be set 
down as altogether erroneous; and if a watch 
does stop in that or any other way, the cause 
of it must be looked for elsewhere. Guided 
by these reflections, those who have hitherto 
entertained such an idea, may probably be 
able to calculate for themselves the chances 
of the setting of a chronometer from the 
effect of external motion. 

Other and more important considerations 
determine, however, the superiority of the 
escapement. We all know the pernicious 
influence of friction. The lever, for instance, 
not to speak of inferior escapements, how- 
ever well all its parts may be executed, can 
never be made so as not to be subject to 
a large share of it ; while in the impulse- 
giving and locking action of the chronometer 
this evil can be reduced to its minimum, 
and hence the acting portions of this escape- 
ment require no oil, which, of itself, is a very 
great advantage. It is the writer's humble 
opinion that this escapement is the only 
one worthy of the tedious labor of the 
adjustment of a compensation balance, as 



well as that of the isochronism of the hair- 
spring. 

But it is the object of these articles to fur- 
nish something of real and practical informa- 
tion to those who are working at the trade, 
and are desirous of learning. It may happen, 
by accident or otherwise, that the spring in a 
chronometer escapement gets broken, or 
needs replacing with a new one for other 
reasons, such as when it has been worked at 
and spoiled by an inexperienced hand ; how 
to replace it properly the following is in- 
tended to show : 

Lines S in Figures 1, 2, 3 represent the 
position of the detent spring in three differ- 
ent escapements. Fig. 1 illustrates that of 
the ordinary English chronometer, where the 
locking takes place at the second tooth from 
the roller, and the spring is in the detent 
itself. Figures 2 and 3 are both of Swiss make, 
where the detents are levers moving on an 
axis, and sprung by a hairspring, and both 
lock at the third tooth from the roller, 
though their positions are different. In Fig. 
1, after G, the centre of the wheel, and G, 
the centre of the balance, are fixed, and the re- 
lative diameters of wheel and roller are devel- 
oped according to principles given in the pre- 
ceding article on the Chronometer Escape- 
ment, the position of the spring and its locking 
point is found in the following manner : From 
the centre, G, a line, E, is drawn, so that it will 
form an angle of 36° with line T ; through 
the point of intersection of this line, and the 
circumference of the wheel, and from the 
centre, C, fine S is drawn, representing the 
line of the detent — its locking point being at 
E. In Figures 2 and 3, with radii, G C, and 
C G, circles M and N are drawn, from the 
point of contact of which, and the centre, G, 
line E is drawn, forming with line T an angle 
of 60° — the distance between two teeth 
and a-half. In Fig. 2, the line S of the 
detent is drawn as in Fig. 1 ; but in Fig. 3 at 
a tangent to the circle of the wheel, and a 
right angle to Hue E, E A being the tangent, 
and the rest afterwards carried out, either in 
a straight line with another right angle at 
the end, or in a curve toward the centre of 
the balance. 

"With respect to the inclination of the lock- 
ing surface of the detent jewel, the writer begs 



AMERICAN HOROLOGICAL JOURNAL. 




28 



AMERICAN HOROLOGICAL JOURNAL. 



leave to correct an indiscrimination in the last 
article, where he says that the locking sur- 
face should form an angle of 12°, with a line 
from the centre of the wheel, which could 
not be admissible in many instances. The 
object of its inclination is to create a draw on 
the detent when the tooth is inlocking. In 
the case of Fig. 1, 12° inclination to a line 
from the centre of the wheel would be almost 
at right angles with the line of the detent, on 
which there could be no draw, owing to the 
position of the locking point in the detent ; 
the line of inclination then should be such, 
that while it is to effect this draw, it should 
not, on the other hand, offer too much resist- 
ance to the unlocking. It dare not be in the 
same line with the inclination of the tooth in 
locking, for to effect a good draw, and create 
the least friction by it, the point of the tooth 
only must be in contact with the surface of 
the jewel. In the case of Fig. 1 then, where 
12° inclination are not sufficient, and the 
tooth would have 26°, we may divide the re- 
mainder, adding it to the 12° ; thus giving 
the detent jewel an inclination of from 18° to 
19°, leaving still enough to the tooth to effect 
a good draw. 

In Fig. 2, the point of locking in the detent 
is such, that the line of the locking surface of 
the jewel can coincide with a line from the 
centre of the wheel ; indeed it dare not be 
otherwise. That in Fig. 3 does not require 
more than 8° or 10° inclination, owing to the 
locking taking place at right angles with the 
line of the detent. 

If, then, a spring is to be made for any of 
the three escapements illustrated, the first 
thing required to be known is, the true place 
of the locking point in it. Point A in the 
diagrams is supposed to be some point in the 
spring which the line S of the detent shall 
bisect, and from which, in Figures 1 and 2, 
the distances to C, the centre of the balance, 
and G, the centre of the wheel, can conveni- 
ently be measured. In Figures 2 and 3, this 
point is the pivot hole of the detent staff; 
but in Fig. 1 it may be the screw hole in the 
foot of the spring ; or better still, one of the 
holes of the steady pins, if such are in the 
line of the detent. The diameter of the es- 
cape wheel must also be measured. Then, by 
trigonometry, in Figs. 1 and 2, we have A, C, G, 



minus C, G, E; C, G, and E, G, as well as the 
angle, C, G, E, being known, the distance, C, E, • 
can readily be found. The value of C E being 
found, subtract it from C A, and the remainder 
will be E A — the distance required to be known. 
In Fig. 3 the work is much more simple, for 
here it is only necessary to measure the dis- 
tance G A, and we have the right angle tri- 
angle G E A, from which those who are ac- 
quainted with Geometry (47 Prop. Euclid) 
will easily find the value of E A. 

For those who are not possessing the knowl- 
edge of these sciences the following method 
for determining the true point of locking may 
serve, which will be equally correct provided 
the workman has a good measuring instru- 
ment as well as drawing tools, without which 
it would be useless to attempt it. Supposing 
a spring, as in Fig. 1, is required to be made ; 
measure the distance C A in the watch accu- 
rately, multiply it by ten, and draw a line 
joining such increased distance, representing 
line S in diagram 1 ; then measure the dis- 
tances A G and C G in the watch, multiply 
each also by ten, and with such increased dis- 
tances as radii, draw circles TJ and V, in the 
point of contact of which circles the true 
centre, G, of the wheel is found ; connect G C 
by line T, and from it and the centre G, lay 
out with a good protractor an angle of 36° 
and draw line E ; now measure the distance 
E A, divide the sum by ten, and the quotient 
will be the actual length from the point A, to 
the true locking point of the detent. If, then, 
this distance is known, the workman may 
proceed to make the spring ; and here it is 
necessary to say that great care is to be exer- 
cised, as well in the choice of the steel as also 
in the preparation thereof. Take several bars 
of the best English square steel, examine 
them in the break and choose that one which 
has the finest grain, and of a silver gray ap- 
pearance ; cut a piece of ample length, draw 
the temper by heating it to a dark cherry red, 
leaving it to cool off slowly ; when cool, ham- 
mer it very evenly, but only on those sides 
which are intended for the sides of the spring, 
and then file the piece up perfectly square, 
i. e., all its sides at right angles with each 
other ; now, over both surfaces which are 
intended for the top and lower side of the 
spring, and through the middle and the whole 



AMERICAN HOROLOGICAL JOURNAL. 



29 



length of it, draw with a sharp steel a distinct 
line — being the line S represented in dia- 
grams 1, 2, 3 ; in this line drill a hole straight 
through the piece for the point A, and at the 
calculated distance from it mark the locking 
point E by drawing a line across the piece 
on the tipper side and at right angles with 
the first line. On this last line a hole for the 
locking jewel must be drilled, and so that the 
line S will cut one-fourth of its whole dia- 
meter on that side which is the inside of the 
spring ; it should be drilled with a drill that 
will make a hole of exactly the size which 
the diameter of the jewel requires, so that 
it will need no reaming out, and on a 
straight-bore machine or on the lathe, in order 
to get it perfectly straight through the piece. 
When this is done the workman may proceed 
to file up the piece ; and, to save a long and 
tedious description of this process, Fig. 4 has 
been drawn, showing the top and inside 
view of a spring according to which pattern 
it may be shaped. Still, though the intelli- 
gent workman will be able to help himself, a 
few points may be particularly noticed for 
his guidance. It is advisable to file up 
D, the foot of the spring, first, and put a 
temporary steady pin in, and bore the hole 
for the screw, so that he will be able to try 
it when filing down the rest of the piece from 
the top to adjust its height to that of the 
wheel ; when this is filed down to the proper 
height the line S must again be drawn over 
the top of it, and in the same way as it was 
before, for this line must guide him in filing 
up the rest to its proper shape. The next 
point is the filing of the round portion at E 
in Fig. I. In order to get this perfectly round 
he may turn up on the lathe two pieces of 
steel like two screws, whose heads shall be of 
exactly the same diameters, and of just the 
size of which the outside diameter of the 
cy finder is to be ; the other part of these two 
pieces must fit the hole for the jewel ; harden 
these pieces and cement one of them in the 
top of the hole, the other into the bottom, 
according to which the rounding can be filed. 
At F a little projection must be left standing, 
just a little higher than the rest of that por- 
tion, which will serve for a bearing to prevent 
the gold spring from turning sideways when 
being screwed on. After all the different 



heights and sides have been filed to their 
proper shape, the length of the point of the 
spring from E on, must be approximately deter- 
mined by trying it with the unlocking roller 
in the watch ; then the spring portion S must 
be filed out, and care must be had that the 
line S will always bisect what is left standing. 
The whole length of this portion may com- 
prise a little more than one-third of the length 
from the foot of the spring to the point, E, of 
locking, and should not be filed too thin yet. 
The hole for the screw which fastens the gold 
spring must then be bored and tapped, after 
which the spring may be hardened. This is 
often done by careful workmen in a small sheet- 
iron box filled with powdered charcoal, into 
which the spring is laid and heated red hot over 
a forge ; but a simpler method is the following : 
Wash the spring well with soap and water, 
dip it into alcohol and dry in fine saw-dust ; 
take a piece of flat steel, considei-ably thicker 
than the spring, and equally as long or longer, 
fasten it upon a good piece of charcoal, lay 
a few other pieces of coal around it so as to 
concentrate the heat, and upon this piece of 
steel lay the spring, after which it may be 
heated with a blowpipe. When it commences 
to get warm, and before it colors, rub the 
upper surface with a little soap and then pro- 
ceed to heat it to a cherry red ; care must be 
had not to blow a pointed flame at it, but 
evenly diffused, and so that the piece of steel 
upon which it lays will become red hot too ; 
when both are cherry red, drop the spring 
vertically into a tumbler of water ; the spring 
should be laid upon the piece of steel so that 
when it drops the heavy end will be for emost. 
If it is hardened in th: : s wise it will be found 
that the side which was touched with soap 
will come out perfectly clean and white ; now 
color it on the blueing pan to a dark yellow, 
and then grind all the surfaces of it with oil- 
stone dust, wash it again in the above men- 
tioned manner, and proceed to temper it to an 
even blue. After this grind all the sur- 
faces again with oil-stone dust to their final 
shape, and by means of a soft piece of 
steel, filed flat, take all the corners 
off and polish them, and then proceed 
to grind the spring portion. To this pur- 
pose the workman should file up a piece of 
brass, as represented in Fig. 5, to be held in 



30 



AMEEICAN HOROLOGICAL JOURNAL. 



the vice. The pins on the top must be at 
such distances apart from each other as the 
width of each portion of the two shoulders 
between which the spring is to be ground out 
requires; and the length of the piece must be 
such, that the spring part will be clear be- 
tween the pins. Tae top should be filed per- 
fectly flat, and the part between the pins 
filed out on each side vertically, so as to allow 
the shoulders of the spring to sink below the 
surface, and the spring to come down flat on 
it ; the whole should be fitted so, that when 
the spring is laid across it, with the spring 
portion between the pins, it should be held 
steady, yet not be cramped. On this piece of 
brass the workman may now, with perfect 
safety, grind down both sides of the spring 
until it is the required thickness, keeping in 
mind all the time that it represents the line 
S in the drawings ; and with a piece of soft 
steel, the corners of which are a little rounded 
off, so that the spring will become a little 
conical from its shoulders, to prevent its 
breaking easily. It should thus be ground 
down to a thickness of 0.03 millimetres. The 
width of the piece of brass, in Fig. 5, should 
be full 15 millimetres, which will prevent the 
side of the spring from becoming rounded or 
uneven. When in this wise the spring is 
finished, the jewel must be cemented in ; but 
before that, the inside of the round portion, 
E, which is to come against the set-screw, 
must be ground flat. To cement the jewel in 
properly, a piece of brass or steel of the same 
size and shape as the jewel must be made 
and fitted into the hole with it, so that they 
are both loose enough to be turned around ; 
cement this piece on to the jewel first, with 
shellac, and afterwards cement them both 
together in the hole. To examine whether 
the surface of the jewel stands at the requi- 
site inclination, say 18° to a line from the 
centre of the wheel, file one side of a brass 
plate straight ; draw a sharp line over the 
surface of the plate, cutting that side at 
angles 95° and 85°, and so, that when the 
plate is held in front of the jewel, and the 
line across it will coincide with the line of 
the detent, the angle 95° will be on the 
outside of the spring ; if now the front surface 
of the jewel coincides with the front of the 
plate, all is right ; if not, it must be made so. 



In reference to finishing up the side sur- 
faces of the spring it may be said that, though 
many workmen pride themselves in doing so, 
it is quite useless to polish them ; a dead oil- 
stone surface will answer all purposes ; 
or a very beautiful ground surface can be 
obtained by using fine powdered sapphire, 
and grinding it in regular lines across the 
piece. Rotten-stone, used on copper, or any 
other metal, will produce a similar surface. 
Much time and labor is often wasted in 
polishing up surfaces, which are of no im- 
portance. Not unfrequently workmen will 
put an exquisite finish on parts which are 
seen in the watch, while they may be altoge- 
ther lacking their geometrical proportion ; 
or the parts which are in action, and ought 
to be well polished, are left rough. Thus, it 
is not seldom that we see a fork in an anchor 
watch beautifully polished on the top surface, 
while the inside of the fork is roughly filed, 
too wide for the ruby pin, and the weight of 
the fork altogether out of poise. Other parts 
of watches are similarly neglected in their 
essential requisites. 

To return once more to our subject, a de- 
tent spring should be made as light as possible, 
for then the spring in it can also be made 
weaker, which will offer less resistance to the 
unlocking, while the locking will be just as safe. 

If an unlocking spring is to be made, it 
should be made of 18 kr. gold, rolled out to 
very nearly the requisite thickness. It can 
be filed by holding it in the sliding tongs 
between two pieces of metal, which must 
previously have been filed straight, and 
should be made a little narrower than the 
front end of the detent. The hole for the 
screw in the foot of it must be bored and the 
end fitted against the bearing on the detent 
so that it will not move side ways when being 
screwed on. Its sides should be ground with 
a fine blue water-stone lengthwise on a broad 
flat piece of steel, holding it down by the 
foot, and only drawing the stone over it from 
the foot towards the front end ; its front end 
should be ground to a thickness of 0.06 mil- 
limetre, and ^diminishing towards the 
foot to 0.02 millimetre. When screwed on 
to the detent it must be bent to its requisite 
shape, so that the front end will rest with a 
little pressure on the end of the detent, tak- 



AMERICAN HOROLOGICAL JOURNAL. 



31 



ing care that the end of it will again coincide 
with line S. Its accurate length can only be 
determined when it is tried in the watch. 

The preceding instructions ought to contain 
sufficient to guide any workman in the mak- 
ing of a detent spring, even should it be re- 
quired to make a spring for either Figure 2 or 
3 of the cuts ; only as in these last the detent 
is not a spring, but a lever moving on an axis, 
a weight must be left standing at the outer 
end to balance the detent perfectly. There 
may be said to be three requisites for the suc- 
cessful accomplishing of the task : first, that 
the workman has good and new files, and not 
very coarse ones ; second, that he understands 
distinctly how the spring is to be made ; and 
third, that he does not cease until he has 
made one so. Th. Gribi. 

"Wilmington, Del.' 



MR. GROSSMAXN'S NEW IMPROVED PENDULUM 
ANALYZED. 



In the last number of the Horological 
Journal there appeared a communication 
from Mr. Grossmann, of Saxony, on the sub- 
ject of a new improved mercurial pendulum. 
As I cannot see any advantage that can be 
gained by using this pendulum over the old 
Graham one, which I know has its faults ; 
and as Mr. Grosssman invites criticism, I reply 
to some of the assertions he advances ; and 
in doing so, I do not wish to be considered arro- 
gant in presuming to review this production 
of your distinguished correspondent in Ger- 
many. 

Mr. G. founds the necessity for his new 
arrangement upon the following experiment : 
" If you suspend two thermometers on a wall, 
the one three feet higher than the other, it 
will be found that in an artificially heated 
room the upper thermometer shows about 3° 
R. (= 7° Eahr.) more heat than the lower 
one, in accordance with well known physical 
laws." I have very frequently placed two 
thermometers, one at each end of a seconds 
pendulum. These pendulums were some- 
times nearly encased in glass, sometimes they 
were partly encased in glass and stone or 
xnarble, and sometimes in wooden cases that 
were placed in rooms artificially heated ; but 



I have never noticed more than about 1° 
Eahr. of difference between the top and bot- 
tom of any of the pendulums. Last winter, 
while experimenting with a new apparatus, 
designed to regulate the supply of heat that 
passed into a room artificially heated by hot- 
air passing through openings in the floor, I 
placed a number of thermometers in the 
apartment, in order to test the regularity of 
its temperature, and there was but a very 
slight difference between those thermometers 
that were but a few feet above the others. In 
talking over the subject in question to a friend 
the other day, he very forcibly and piquantly 
said " that if that was so, a man six feet high, 
and the heat of his body being in a state of 
perfect equilibrium, would suddenly find his 
head to be 14° warmer than his feet, in going 
into an artificially heated room in winter ;" a 
sensation which probably few people have 
experienced in this part of the world. 

I admit that there is some difference be- 
tween the temperature of the air near the floor 
of a room, and the air near the ceiling ; but it 
must be only under very peculiar circumstan- 
ces that so much difference as nearly 7° Fahr. 
takes place in the short distance of three 
feet ; and most assuredly that difference does 
not exist between the two ends of pendulums, 
in the position clocks are usually placed, 
whether they be in inhabited rooms or in As- 
tronomical Observatories. 

Mr. G. further considers that " the mer- 
curial pendulum, which performs admirably 
in an Astronomical Observatory, generally 
fails in parlors and inhabited rooms." The 
stores and shops of marine chronometer 
makers, may, in many instances, be considered 
analogous to parlors or inhabited rooms ; 
and I will venture to state that at the present 
day a majority of the marine chronometers 
in the world are rated from clocks placed 
in these rooms, and having Graham pendu- 
lums. I have never seen or heard of an in- 
stance where a clock made with the most 
ordinary care, failed to answer every purpose 
of a private dwelling on account of it having 
a Graham pendulum. No house clocks are 
liable to be subjected to greater or more 
sudden changes of temperature than those 
that are employed in Astronomical Observa- 
tories, where the system of observing by tha 



32 



AMERICAN HOROLOGICAL JOURNAL. 



eye and the ear is still maintained ; for when 
the shutters in the roof, or in the dome, are 
opened, the clocks are subjected to whatever 
extremes of temperature may be outside ; yet 
under these severe ordeals the Graham pen- 
dulum has earned the reputation it holds at 
the present day. 

Having discussed the question of tempera- 
ture, I will now proceed to consider the sub- 
ject of Mr. Grossmann's improvements ; but 
I would first notice that the pendulum he 
gives us will not beat seconds with a ball 
17.7 in. long, and the total length of the pen- 
dulum only about 48.43 in. With such a 
heavy rod it must be made considerable 
longer to do so. However, this may simply 
be a mistake, and in no way does it compro- 
mise the principles involved in tbe pendulum 
itself. 

For his improvements, Mr. G. claims as 
follows : 

" It will be easily seen that this arrange- 
ment has the following advantages : 

" 1. Equal thickness of the compensating 
parts, and, in consequence of this, equal sen- 
sibility of the same to changes of temperature. 
(The trifling difference between the diameter 
of zinc rod and that of iron jars or tubes will 
be made up by the greater heat-conducting 
power of the iron.)" 

This is also the idea of Mr. Coffinberry, of 
Grand Rapids, Mich., that the rod should be 
the same thickness as the column of mercury, 
in order that they may be equally affected, 
by a sudden change of temperature, exactly 
at the same time. Apparently this is a plau- 
sible theory, and doubtless the size of the 
one should bear a relative proportion to the 
size of the other ; but to make them the same 
is a fallacy ; it is fallacious in various ways. 
In seeking for compensation, the fundamen- 
tal laws upon which the fabric of the pendu- 
lum is built are violated — gives the pendulum a 
much longer length than is necessary, and 
increases rather than diminishes the difficulty 
of compensation. If the materials that com- 
pose the pendulum had all the same natural 
properties for absorbing and radiating heat, 
and if the pendulum stood at rest, like a ther- 
mometer, then there might be a necessity for 
having all the parts of the same thickness ; 
but this is not so. And further, when the 
pendulum is in motion the mercury passes 



through a greater space of air than the rod, 
and renders it liable from that cause, in 
addition to its natural sensitiveness, to be 
acted upon before the small rod is affected. 

It is quite common in some parts of the 
world to place a piece of plate glass inside 
the case, in front of the pendulum ball, to 
protect the mercury from sudden changes if 
the clock chances to stand before a door, and 
good results are said to follow. Personally I 
am convinced, that as a general thing the 
mercury is acted upon before the rod ; and 
were this not the fact, the short column of 
rnercury usually employed for steel rods 
would not do the work it does. (See page 
31], Vol. I.) 

The next claim contains the distinctive fea- 
ture of the pendulum : 

" 2. Considerable diminution of the defect 
of compensation in the mercurial pendulum, 
arising from the difference of temperature in 
the different heights in which the compen- 
sating elements are moving. In Graham's 
mercurial pendulum the mercury constitutes 
about the sixth part of the length of the pen- 
dulum, while the rod, beginning above the 
mercury, makes up the other five-sixths of it. 
The above-described improved mercurial 
pendulum has its zinc rod passing through 
the frame down to the lower end of the pen- 
dulum, and the mercury column constitutes 
more than one-third of the total length." 

The inventor, unlike all other inventors 
that have preceded him, has selected a metal 
that will expand the most, to make the rod, 
in preference to one that will expand the 
least, as is usually done. The object of this 
selection is, that the columns of mercury will, 
of a necessity, be much longer than usual, in 
order to compensate the extra expansion of 
the rod, and thereby have the top of the mer- 
cury nearer the top of the rod, with the in- 
tention that it will, as nearly as possible, be 
subject to the same temperature as the rod, 
and make it move like the Gridiron pendu- 
lum, whose compensating rods accompany 
each other, side by side, nearly the entire 
length of the pendulum. Mr. G. appears to 
forget that the principles of compensation in 
the Graham and his own proposed pendulum, 
are altogether different from the Gridiron. 
In the one the effects of the expansion of 
the rod is counteracted by the ball being in- 
creased or diminished in length, while in 



AMERICAN HOROLOGICAL JOURNAL. 



33 



the other the entire ball is raised up or let 
down. 

I will illustrate by a familiar example what 
would be the practical effect of having columns 
of mercury extend so high above the centre 
of oscillation — and the inventor would have 
these columns extend to the top could he so 
arrange it. It is customary, sometimes, to 
regulate a pendulum by a small weight that 
shifts up and down on the pondulum rod. 
Huyghens demonstrated the theory of this 
method of regulation, aud he graduated a 
scale to show how much the small ball had to 
be shifted to make a given alteration in the 
rate of the clock. These graduations vary in 
length, as the weight ascends the rod, till a 
point is reached that whether the weight is 
moved up or down, the effect on the rate of 
the clock is the same. Mr. G. makes the mer- 
cury to come up to about 20.73 in. from the 
point of suspension, and Graham has about 
36 in. From Huyghens' demonstration it 
will be observed that the expansion of the 
mercury columns will have a variation in their 
value as the length of the columns extend up 
the rod ; for, as previously stated, the entire 
effective weight of the ball is not raised by 
expansion or lowered by contraction, but 
only part of it ; and if these mercury columns 
were extended to a given point between 
the centre of oscillation and the point of sus- 
pension, the effect of the compensation 
would be nearly, if not altogether, neutralized. 

In contradistinction to Mr. Grossmann's 
pendulum, I will instance the glass one, 
where the cylinder and rod are blown in one 
piece. These pendulums are very rare, but 
it has often occurred to me that it was the 
best way a pendulum on Graham's plan 
could be made. The little expansion of the 
material takes but a short column of mercury 
to compensate it, and allows the mass that 
constitutes the pendulum to be concentrated 
as far away from the point of suspension as 
possible, and thereby comes nearer to the 
ideal pendulum of "a material point sus- 
pended by an imaginary line," than any other 
form of compensation pendulum that there 
is. 

The inventor also claims : 

" 3. Reduction of the resistance of the air 
to the least amount." 



Galileo first gave ocular demonstration, 
from the Leaning Tower of Pisa, in Italy, that 
if two bodies of the same form and density, 
but of different sizes, are let fall from a given 
point at the same time, they will reach the 
ground together. This same law governs the 
motion of the pendulum ; and according to 
Galileo's indisputable theory, one of Mr. 
Grossmann's small jars meets the same resist- 
ance as Graham's large one ; they being both 
of the same shape, and being both filled with 
mercury, are of the same density, although 
very different in size. Let us look at it from 
another view, having no connection with this 
law. Graham has a cylinder about 2 in. 
diameter, and 7 in. long, which by calculation 
gives an outside surface of 43.4 in. Gross- 
mann has four cylinders, each 0.73 in. diame- 
ter, and 17.7 in. long, which makes the outside 
surface 160.2 in. If the nature of the resist- 
ance of bodies passing slowly through the 
air, be the same as bodies passing through 
water, only in a proportionably less degree, 
the result must be greatly in favor of the 
Graham pendulum. To recapitulate : Gra- 
ham's one jar has an outside surface resist- 
ance of 43.4 in., while Grossman's four jars 
have 160.2 in. of surface exposed to the air. 

I have now gone over all the distinguish- 
ing features of this pendulum, and I hope 
that the reader will reflect and consider the 
subject well. Remember that the error that 
is to be cured is not one of several seconds, 
but of tenths of seconds. The nearer we get 
to perfection the approach becomes the more 
difficult. However simple it may seem at 
first, it is a subject closely allied to a great 
many other intricate questions, and superfi- 
cial thinking, or looking only from one point, 
will not do. I hope that this discussion will 
continue till we get a correct compensation 
pendulum. 

I believe, in the Patent Laws generally; it 
is the inalienable right of every man to receive 
all due credit and protection for his ideas or 
productions ; but while that is my expressed 
belief, I hope that we will have no more patent 
pendulums ; they savor too much of patent 
medicine. It is a subject too sublime, and of 
too little commercial importance, to be made 
the subject of a patent. Probably I work as 
hard, and spend as much time on this ques- 



34 



AMERICAN HOROLOGICAL JOURNAL. 



lion, as most people; yet I would as soon 
think of taking a patent out for a pendulum, 
as I would if I was successful in squaring 
the circle, or solving any other equally diffi- 
cult problem. 

Clyde. 



HEAT. 



NUMBER ONE. 



INTRODUCTION. CALORIC IS HEAT A SUBSTANCE? 

OPINIONS AND EXPERIMENTS OF PHILOSOPHERS 

CONCERNING IT, ETC. 

In this number we commence a series of 
ai tides on Heat, designed to be of general 
interest. We propose to exhaust this com- 
prehensive subject in a series of papers de- 
scribing the nature and effects of heat in 
general, — the laws of its transmission — its 
effects on all bodies, especially metals — and 
its practical application to the many mechani- 
cal arts interesting to the Horological com- 
munity. 

Heat is unquestionably one of the most im- 
portant agents employed by nature in form- 
ing the constitution of bodies, and in pro- 
ducing that unceasing change observable in 
the animal, vegetable and mineral kingdoms. 
There is scarcely any department of physical 
science in which the nature and properties of 
heat do not in some way enter into our con- 
sideration. The meaning of the word heat is 
so well understood, that any attempt to 
define it is unnecessary. When we say that 
a person feels heat, or that a piece of metal is 
hot, the expression we understand readily ; 
yet in each of these propositions the word 
heat has a distinct meaning. In the first it 
signifies the sensation of heat, and in the 
other the cause of that sensation. To avoid 
the supposed ambiguity of these two mean- 
ings to one word, the term caloric was in- 
vented by the French to signify the cause of 
heat. When you place your hand on a hot 
piece of metal, you experience a certain sen- 
sation which is called the sensation of heat. 
The cause of this sensation is caloric. In 
ancient philosophy it was commonly said 
ihat heat occasioned the warmth and expan- 
sion of bodies, and likewise that heat was 
excited in bodies by the addition of some 



peculiar kind of matter, or by a certain modi- 
fication of their particles. The more precise 
nomenclature of the moderns has tended to 
correct this error, and led to the invention of 
the new term caloric, to designate the cause, 
while the word heat is, strictly speaking, only 
applicable to the effect. As, however, in all 
the older authors, the former phraseology 
necessarily exists as it is adopted in popular 
language, there is no danger of falling into 
any error, since the distinction has been so 
fully pointed out ; the word heat is frequently 
used in this double sense, even by the latest 
and most correct writers, and it will be used 
by us in this way in the following articles. 

Two opinions respecting the nature of heat 
have divided philosophers. According to 
some, like gravity, it is merely a property of 
matter ; while others contend that it is a 
substance, capable of a separate existence, 
and possessing a material, although very sub- 
tile, nature. The latter opinion was at first 
broached by the chemists, and at present is 
acceded to by nearly all philosophers ; yet 
there are, on the contraiy, many eminent 
men who regard it merely as a property 
necessarily attached to other matter, and 
arising from some peculiar modification or 
affection of it. Bacon adopted the latter 
opinion, and conceived that heat depended 
on a vibration of the particles of matter ; a 
hypothesis which he advanced to substantiate 
by showing that whatever excited tempera- 
ture tended also to produce a motion in the 
particles of the heated body. His description 
of that peculiar nature signifies " a reaction 
between the expansive force of heat and the 
attractive force of the particles of matter 
toward each other." The idea of Bacon, that 
heat depends on a vibratory motion among 
the particles of matter, received the powerful 
sanction of Sir Isaac Newton ; but as observa- 
tions on the phenomena of nature were multi- 
plied, and especially as chemical science 
advanced, the hypothesis which considered 
heat as merely consisting in the motion of 
particles in matter appeared less easy to re- 
concile with the new discoveries, and conse- 
quently a different doctrine was advanced, 
in which the effects of heat were attributed 
to a species of subtile fluid, of a proper 
material nature, although differing in many 



AMERICAN HOKOLOGICAL JOURNAL. 



35 



important particulars from any other kind of 
matter. 

Our limits will not permit us to take a very- 
full view of all the arguments that have been 
urged on both sides of the question ; but we 
must endeavor to give a sketch of some of the 
principal points that have been adduced by the 
advocates of each of these opinions. It will 
Scarcely be denied that if we admit the exist- 
ence of a subtile elastic fluid, the particles of 
which are endowed with a repulsive power 
which tends to unite itself to all kinds of 
matter — to insinuate itself into their pores — 
to produce their expansion, and, if added in 
sufficient quantity, to impart to them its own 
elastic nature, we are possessed of an agent 
which very conveniently explains a great 
variety of phenomena ; but this hypothesis, 
however, has been strongly opposed by 
Rumford on the strength of the following 
experiment of developing heat by friction. 
A piece of brass was fixed in a machine for 
boring cannon, and a steel cylinder was 
pressed against the brass, with a force equal 
to 1,000 lbs., and then made to revolve on its 
axis with a given velocity. After some pre- 
paratory experiments the apparatus was all 
enclosed in a vessel of water, and after the 
friction had been kept up for some time, the 
water was actually brought to the boiling 
heat. Here a very considerable quantity of 
heat was liberated, and the only mechanical 
change effected on the materials, was that a 
quantity of brass turnings or scrapings were 
formed ; but neither the brass nor the cylinder 
itself appears to have experienced any 
change, except a slight degree of compres- 
sion. Rumford found, by experiment, that 
the capacity of these turnings or scrapings 
would not be affected by the operation ; and 
the effect of the compression which the 
metal had experienced, must have been very 
inconsiderable ; yet, the power of the sub- 
stance to extricate heat was apparently un- 
limited ; for there is no reason to suppose 
that anything like exhaustion was produced, 
or that the apparatus would not have con- 
tinued to evolve heat, until its texture had 
been destroyed by the brass being all reduced 
to fragments. 

Although there is no direct experiment to 
prove the independent existence of heat, as a 



material substance, there are none except 
those of Rumford, and some of a similar 
nature, to prove the immaterial doctrine. 
Besides, although we have admitted that 
there is no direct experiment to prove the 
independent existence of heat, or at least 
none against which some exception has not 
been taken, yet there are facts brought for- 
ward, perhaps as decisive on the one side as 
those of friction on the other. We refer 
to the transmission of heat through a 
vacuum. Pictet proved that this takes 
place in the vacuum of the air-pump, and 
Rumford himself has shown it is capable 
of passing even through the Torricellian 
vacuum. 

There seems no method of reconciling this 
fact with the hypothesis, except taking for 
granted the existence of some kind of vapor 
or elastic fluid, with which it is propagated ; 
a supposition equally gratuitous, and equally 
unsupported by direct and independent facts, 
as that for which it is substituted. It seems 
extremely improbable, if not impossible, 
that rays of heat are carried along by the 
air, even when near the surface of the earth, 
and in coming from the sun they must 
necessarily travel an immense distance totally 
devoid of air. Herschel, while employed in 
examining the sun by means of telescopes, 
thought of examining the heating powers of 
the different rays of light, separated by the 
prism. He found the most refrangible rays 
had the least heating power, and that the 
heating power gradually increases as the re- 
frangibility diminishes. The violet rays have 
of course the least, and the red rays the 
greatest heating power. It struck Dr. 
Herschel as remarkable that the illuminating 
power and heating power follow different 
laws — the illuminating power being greatest 
in the middle of the spectrum, and the heat- 
ing power being greatest at the red end. 
This led him to consider that the heating 
power did not stop at the end of the spec- 
trum. On trying the experiment he found 
that a thermometer placed a little beyond the 
spectrum rose still higher than in the red 
ray ; hence it follows that there are rays 
emitted from the sun which produce heat, 
but have no power of illumination ; conse- 
quently, heat is emitted from the sun in rays, 



36 



AMEKICAN HOBOLOGICAL JOURNAL 



and the rays of heat are not the same as the 
rays of light. 

Professor Leslie, to whom science is so 
mnch indebted for so many experiments, 
adopted the hypothesis which ascribed the 
effects of heat to a certain motion among the 
particles of bodies. He conceives that the 
propagation and transmission of heat is very 
similar to that of sound ; and, in fact, it con- 
sists of certain aerial undulations. The pas- 
sage of heat is, therefore, of the same velocity 
with the undulation of the air, or, rather, is 
identical with it. Professor Leslie, however, 
seems to have advanced this hypothesis 
merely as a convenient manner of accounting 
for his own experiments. He has not stated 
it in such a way as to apply to all the phenom- 
ena of heat, nor has he attempted to recon- 
cile it with the experiments of Herschel and 
others, which appear decidedly adverse to it. 

Before we conclude these observations con- 
cerning the immateriality of heat, it will be 
proper to notice the experiments which have 
been made, in order to ascertain whether it 
be actually possessed of gravity, or, rather, 
whether its weight can be measured by a 
balance. The best contrived experiments of 
this description were those of Fordyce. He 
very carefully weighed a quantity of water ; 
froze the water, and then again weighed it. 
Now, he argued that in this process the water 
must have parted with the latent heat which 
maintained it in a liquid form ; so that if 
heat be a ponderable substance it might be 
expected that the ice would exhibit a diminu- 
tion in its weight equivalent to that of the 
caloric which had escaped. The result, how- 
ever, did not correspond with this idea ; and, 
indeed, in some of the most accurate trials it 
seemed as if the body that had parted with 
its heat had even acquired a slight addition 
of weight. It is, however, generally admitted 
that no decisive conclusion can be drawn from 
such experiments, and that from the concep- 
tion that we have of the extreme tenuity of 
heat, it is not probable that any portion which 
we can have in our power to impart to a body 
could be detected by the instruments that we 
employ in ascertaining the weight of bodies. 

The further consideration of this subject 
would involve us in a discussion that would 
exceed the limits to which we are necessarily 



restricted. Upon the whole, we are strongly 
inclined to the opinion in favor of the ma- 
teriality of heat, because we think it explains 
the phenomena in general with greater 
facility, and is encumbered with less difficul- 
ties than the immaterial hypothesis ; yet we 
must remember that it is not decisively proved 
by any direct or unexceptional experiments, 
and it must also be acknowledged that it has 
not received the sanction of some eminent 
philosophers, both in comparatively ancient 
and also in modern times. 



THE COMING WORKMEN. 



How are they to be educated ? is a problem 
which seems to be troublesome to solve. At 
present there is no scarcity of workmen of a 
sort, but really good ones are very difficult to 
obtain. By good ones we do not mean abso- 
lutely scientific as well as practical, but 
simply good practical mechanics. Thoroughly 
educated ones we never can expect to find as 
a class, so long as the community are ignor- 
ant of the requirements for a good mechanic. 
As things now are, hand workers, without 
heads, answer better the demand of the public, 
which is cheapness, than any other class ; and 
until they are brought by dearly purchased 
experience to see the folly of squandering 
money on that class of workmen, there is no 
use to urge a higher standard of qualification. 
But even the race of passably good hand 
workers seems to be in danger of extermina- 
tion. The old mode of education seems 
nearly obsolete ; there are no adequate means 
(legal) to compel persons to become profi- 
cients ; the apprenticeship laws are a dead 
letter, even the " one cent reward " with the 
picture of a lad with a bundle over his 
shoulder suspended on a stick, has disappear- 
ed from the newspaper advertisements, and 
with its disappearance all vestige of the 
mechanical apprenticeship system seems to 
have vanished, and the trade seem to have 
settled themselves down to the belief that for 
anything like fair workmen they must depend 
upon chance foreigners, who are often driven 
to emigrate from their own country for lack 
of the requisite skill to find employment in 
it. For the rough work, requiring no skill, 



AMERICAN HOROLOGICAL JOURNAL. 



37 



they depend upon boys who happen along 
and " want to learn the trade," and they 
manage to use them to open shop, sweep out, 
run of errands, turn grindstone, and tinker 
clocks, till they are filled to overflowing with 
the idea of having a shop of their own to 
open, and being themselves "proprietors." 
These are the kind of workmen that are 
turned loose upon the community to supply 
the craving call for cheap labor. 

No really good mechanic, who knows his 
ability and takes a manly pride in it, will be 
annoyed by such apprentices ; there is no 
profit in it, no pleasure, and no pride in it ; 
the artisan feels that his profession is dis- 
graced by turning cut such men, and calling 
them workmen. But the 'dear [public stand 
with mouths wide agape, like little birdlings 
in a nest, clamoring to be stuffed with a big 
morsel of " Humbug," and so they swallow 
the cheapest workman and are satisfied. 
Humbug grows rich and fat, and honest 
skill can scarcely make the two ends meet. 
The only remedy for this state of things is 
to educate the public to know and realize the 
irurueasurable distance there is between the 
two, and in some little degree be brought to 
understand the necessity for real scientific 
skill in the repair of watches, even more than 
in their construction ; then they would be 
more cautious about intrusting their watches 
to the ignorant workman. 

Our requirements here for a workman 
who can truly be called good are somewhat 
different from the European standard. In 
the United States what little constructing 
is done is confined exclusively to the estab- 
lished factories, and all the knowledge re- 
quired of the workmen in them is, dexterity 
in running the various machines. The tech- 
nical science required in the original design- 
ing and laying out the work is not required 
in the subsequent mechanical manipulations. 
A thorough understanding how to lay out the 
work, define the proper place for each part, 
and determine, with the positive accuracy of 
science, the proper proportion which each 
part should bear to every other part, and 
with the requisite knowledge of isometrical 
drawing to transfer the design to paper, is 
the mental capital absolutely necessary to 
start a watch factory. Then, when the proper 



automatic machines are constructed, only 
art is required to run them. 

Abroad, both in England and on the conti- 
nent, each manufacturer gets up his own 
design, plans his own particular make of 
watch, and its performance and quality as a 
timekeeper are in exact proportion to his ap- 
proximation to scientific principles of con- 
struction. For it is established incontro- 
vertibly that there are positive laws of 
proportion applicable to every part of a 
watch, which cannot be violated without loss 
of effect. The consequence of this diversity 
of design and construction is an equal 
diversity of watches that are cast upon the 
market. What workman of experience does 
not know the difference between Coventry 
and Clerkenwell movements ? There is 
scarcely more difference between a Paris and 
a Swartzwald clock. 

The British Horological Institute was estab- 
lished for the purpose of correcting, if pos- 
sible, this difficulty, which seemed to threaten 
serious damage to the whole watch trade of 
England. The Institute is laboring earnestly 
to establish classes of workmen for instruc- 
tion in the principles of the art. Believing 
that science can only add to, not detract 
from, a man's ability, however expert he may 
be in a practical point of view, and that " ex- 
perience, however extended, could not but be 
profited by the acquisition of facts, wherever 
gathered, from learned men of all ages," and 
to teach such facts, and to communicate all 
such scientific knowledge as is applicable to 
Horology, is the primary object of the Insti- 
tute. Here, with us, we are particularly in 
want of this knowledge, for the whole busi- 
ness of the American watchmaker is to mend, 
not make. America seems to be the heaven 
of poor watch workers. An English or Swiss 
movement, so defective in its construction as 
to prevent its sale at home, is good enough 
for export, and will sell in " The States." No 
sooner do such movements pass the Custom 
House than they are sent broadcast over the 
country by Express, CO. D., and the watch- 
maker, wherever it goes, is required to make 
it run, and for ever after to stand godfather 
to the wretched production cast upon the 
world and deserted by its depraved parent. 
Now, the skill required to make that watch 



38 



AMEKICAN HOKOLOGICAL JOUKNAL. 



go must be far in excess of the knowledge 
displayed in its construction, and unless a 
■workman knows why and where it is defec- 
tive, in spite of its high finish, he may puzzle 
his brains till doomsday and be no nearer 
ascertaining the true cause of its misbehavior. 
And this same ignorance of the true principles 
upon which it should be constructed is the 
real cause of nine-tenths of the watches being 
further spoiled in the hands of this incom- 
petent class of workmen. They have no idea 
what is the matter, and the consequence is 
that every screw and wheel, and pinion and 
pivot, and cock and bridge, is filed, and bent, 
and twisted, in the faint hope that some of 
these^ various punchings may, by accident, hit 
the real difficulty. Their mode of treatment 
is the same as that of an ignorant physician, 
who, in case the patient's disease is quite un- 
known to him, administers remedies at 
random, with the forlorn hope that some one 
of them will cure. 

This brings us face to face with the ques- 
tion, How is this state of the craft to be 
bettered? All good men deplore the situa- 
tion, and some, no doubt, have theories as to 
the best plan of remedy. Our own pet theory 
is, the reformation of the community with re- 
gard to the support they give to the most un- 
worthy workman. But how to bring about this 
reformation is the question. All must feel the 
truth of the assertion that public opinion 
cannot be driven, it must be led; humans, 
like those quadrupeds whose ears are not 
proverbially short, have a preponderance of 
inertia — a tendency not to move, but when 
once in motion in any given direction the 
tendency is equally strong not to stop. These 
little whimsical peculiarities of the public 
mind make it necessary to resort to an ex- 
pedient that boys adopt to change the direc- 
tion of a rolling hoop, without throwing it 
down — that of applying a gentle pressure, so 
as gradually to change its direction. Of 
course it takes time to do this ; but if five 
hundred resolute, good men (and we think 
there are more than that number in the trade), 
set themselves seriously and earnestly about 
it, good results may be expected in a reason- 
ably short time. The general idea of the 
method to adopt would be for each workman 
to earnestly impress upon the owner of any 



watch, that chanced to come in his hands, 
the necessity of carefulness in workmen ; he 
could easily be shown, in his own watch, 
where it had been marred and disfigured, 
and he could, in a five minutes talk, be made 
to understand that all the real damage that 
could possibly happen to the watch in the 
the owner's hands, would not permanently 
injure it in the least if properly repaired. On 
no account must he get the impression that 
you are talking against any particular work- 
man, for then your whole harangue will be 
set down as trade jealousv. In converting 
him from the error of his ways, you will more 
than probably make for yourself a permanent 
customer, and at the same time will, in him, 
send out a missionary who will sow more of 
the good seed. There is no better way to 
make a man careful to whom he intrusts his 
watch work, than to convince him that it can 
be so easily spoiled. Now, all this can be 
brought about by simply telling the truth, 
for we all know these things to be facts. 
Were it necessary for us, as craftsmen, to 
make out our case by lying, or even with- 
holding the truth, we should be the very last 
to make the proposal ; but it is truly serving 
the community, as well as ourselves. As soon 
as the public demand thoroughly competent 
workmen, we doubt not but the means to 
supply them will not be wanting. 

As our Journal is designed for a free and 
full interchange of individual opinions, for 
the good of the whole, we should be exceed- 
ingly glad to have any who have given the sub- 
ject a thought communicate with us, either 
in private or public. We hold no " patent " on 
our opinions, and will give earnest attention 
to any suggestions by any of our subscribers ; 
for by such means we hope to arrive at the 
best mode for the solution of a difficult prob- 
lem. 

o 

figg"" In the article of Mr. Grossmann's on 
the Mercurial Pendulum, in the July No., for 
" Weight of Mercury Columns," in the table, 
read " Height of Mercury Columns." Typo- 
graphical errors are very annoying, but seem 
to be unavoidable. Also, the article on Iso- 
chronism should have been credited as com- 
ing originally from Mr. Fordsham, of Lon- 
don. 



AMEKICAN HOROLOGICAL JOURNAL. 



39 



ISOCHRONISM. 



It is a -well-known fact that when a watch 
has been running a length of time after hav- 
ing been put in order, the arcs of vibration 
of the balance grow smaller in proportion to 
the thickening of the oil, which not only pre- 
vents the balance from describing its original 
arc of vibration, but occasions a " drag" on 
all the frictional parts of the watch, whereby 
a part of the motive power of the main-spring 
is exhausted, and the regulator prevented from 
exercising its original influence. In addition 
to this, the watch is also subjected to almost 
continual outer motion consequent upon 
usage. These facts, taken together, tend to 
interfere with the free motion of the balance, 
and an irregularity in the going of the watch 
is the consequence ; which, unless those faults 
can be corrected, renders it valueless where 
correct time is required. 

As it is not possible to remedy these in- 
equalities in the arcs of vibration, we are 
compelled to resort to other means by which 
unequal (large or small) vibrations become 
of equal duration, and this can only be ac- 
complished by means of the hair-spring. 

The method universally adopted of making 
the vibrations isochronous embodies the prin- 
ciple that a very short hair-spring, whose 
whole length is of equal strength, impels large 
vibrations to move faster than small ones ; 
and a very large hair-spring, with the same 
conditions, causes the large vibrations to move 
slower than the small ones. If, then, it is 
desired to make the vibrations isochronous, a 
hair-spring must be selected between these 
two extremes, in which large and small 
vibrations become of equal duration. The 
exact size of the spring cannot be determined 
beforehand, but must actually be tested in 
the watch, as it not only stands in proportion 
to the weight and diameter of the balance, 
but to the strength of the pivots, and the form 
of the jewel holes. 

Experience has shown that the cylindrical 
spring is the best to establish a correct 
isochronism, as the coils are all equally dis- 
tant from the centre, whereby the movement 
of the coils in the long and short vibrations 
becomes equal. The diameter of the cylindri- 
cal hair-sx->ring should be one-third that of 



the balance, with about 8 or 9 coils. When 
there is not sufficient height to admit of that 
number of coils, they may be lessened ; but 
the diameter must be increased in proportion, 
as a certain length cannot be deviated from. 

The Breguet hair-spring is also a very good 
one with which to establish a correct isochron- 
ism. In form it is flat, with the outer coil 
bent upwards, and parallel with the remain- 
der of the spring, and forming a part of its 
circle. The outer coil should be so placed 
that it be from 1 to 1| coils above the centre 
of the spring from the inner to the outer coil. 
The movement of the coils in this spring are 
very even, which is a condition required to 
establish a correct isochronism. When select- 
ing a flat spring, one should be chosen with the 
coils wound as closely as possible, which ren- 
ders the movement of the coils more even 
than one whose length is the same, but whose 
coils are farther apart. In adjusting the ends 
of the spring they should be so pinned that 
one end stands exactly over the other ; or, 
which is the same thing, that the ends form a 
right angle to the centre, which position, ex- 
perience has shown, tends to lighten the task 
of regulating. Indeed, some authorities on 
this subject have gone so far as to claim that 
an exact isochronism can be obtained by this 
means alone. This theory is, however, new, 
having been recently put forth by Mr. E. 
Sandoz, of Springfield, Mass., whose reputa- 
tion as a " springer" is undoubted. Having 
never made any experiments on his theory, 
of course I can give no results. 

From these considerations we may deduce 
the fact, that a correct isochronism may be 
attained by altering the length of the spring, 
either longer or shorter, so that the large 
and small vibrations may be made to go 
faster or slower, as occasion may require. My 
experience has shown that an exact isochron- 
ism is not always desirable. For instance, 
allowing the small vibrations to describe 
somewhat faster than the large vibrations, so 
that a watch, say with arcs of vibration of 350°, 
regulated to mean time, and then falling off to 
150°, should gain five or six seconds in twenty- 
four hours in the small vibration. The rea- 
son of this is, that after the watch has been 
running a length of time the hair-spring 
tends somewhat to " draw," whereby a very 



40 



AMERICAN HOROLOGICAL JOURNAL. 



little irregularity is perceptible ; then there is 
the thickening of the oil on the balance and 
train pivots to be considered, which causes a 
loss of motion of the balance, and an irregu- 
lar rate in the running of the watch. 

Another reason why a perfect isochronoiis 
spring should not be used, is, that if the fric- 
tion of the pivots of the balance staff, when 
in a horizontal or vertical position, remains 
the same in a temperature of 14 to 18° R., 
the motion of the balance will be the same ; 
but should the watch be placed in a tempera- 
ture below zero, the friction of the pivots 
would be increased, and the motion would 
not be the same, and the watch would not 
have a regular rate. This would be more 
perceptible in a vertical position, as the arcs 
of vibration would become smaller, thereby 
causing the watch to lose time. If, then, a 
spring shall be selected that will cause the 
watch, in the small vibrations, to gain as 
many seconds as it would lose by reason of 
the thickening of the oil and the other rea- 
sons mentioned, a degree of regularity would 
be acquired that would be maintained in any 
temperature. 

I will now endeavor, in as few words as 
possible, to show how the proper length of 
hair-spring may be determined, so that the 
above conditions may be fulfilled. The watch 
should first be in good running order before 
the isochronism of the spring is tested. This 
being observed, and the watch being fully 
wound up, set the hands to the correct time, 
as indicated by a regulator that can be de- 
pended upon, and let it run twelve hours. 
At the end of this time let the difference of 
time between the watch and the regulator be 
carefully noted. Now let down the ratchet 
so that a very little motive power is exerted, 
or substitute a weaker main-spring, and then 
carefully set the hands with the regulator, 
let the watch run another twelve hours, and 
then compare the difference between the first 
and last running. Should the watch have 
gained two or three seconds in the small 
vibrations (last experiment), then the 
hair-spring is one very well adapted to 
the watch. But should it have gained 
more than that, or, on the contrary, lost 
two or three seconds, then the spring is 
not well adapted to the watch, and its length 



must be altered, according to the results ob- 
tained by the experiment. It is often the 
case that not till after many experiments have 
been made, and repeated changes of the 
spring, that the efforts of the artisan are re- 
warded with success. Chas. Spieo. 



DIALING. 



NUMBER TWO. 



Knowing that there are many persons in 
the trade who do not fully understand some 
of the terms which will be found often 
repeated hereafter, and who probably will not 
take the trouble to search out their precise 
meaning, but may be incited to study them in 
this connection, therefore we think it best to 
devote more space to definitions than will be 
thought necessary by the educated, who are 
prone to assume that everybody knows these 
things. Having mingled much with crafts- 
men, and having found among them a great 
want of scientific knowledge, not that it is 
undervalued by them, but the opportunity to 
acquire it has never been presented, therefore 
we must take people as we find them, and do 
our best to leave them in a better condition. 

Right {or Straight) Line. — The nearest dis- 
tance between two points. 

Arc. — Any part of the circumference of a 
circle or other curve. 

Radius. — Line or distance from the centre 
to the circumference of a circle, always equal 
to the semi-diameter of the circle. 

Tangent. — A right line which touches a 
curve, but which, when produced or continu- 
ed, does not cut it ; is always perpendicular 
(or at right angles) to the radius. 

Chord. — A right line joining the two 
extremities of an arc — like the string of a bow. 

Degree. — The 360th part of a circle ; it is 
no definite quantity, or distance, for every 
circle, whatever its diameter may be, is sup- 
posed to be divided into 360 equal parts. 

Angle — Is the number of degrees contained 
between any two radii of a circle. The angle 
between any two lines is the same, whether the 
lines extend an inch, or a million of miles. 

Right Angle. — Quadrature, or quarter of a 
circle, and is 90° of the circle. 

Complement of an arc or angle, is what the 



AMERICAN HOROLOGICAL JOURNAL. 



41 




arc or angle lacks of being 90° ; thus, if an 
angle or arc is 60°, its complement is 30°. 

To construct or draw a right angle, as in 
Fig. 1, or raise a perpen- 
dicular to the line A B, 
set your compass in the 
line B, and with an open- 
ing greater than half the 
line, describe the two 
arcs, G F and S J ; from 
A, with the same opening, 
describe the arcs D E, 
and LK; lay your rule 
on the intersections of the 
arcs, and draw H C, 
which will be perpendicu- 
lar to A B, and the angle contained between 
A C H, or H C B, is a right angle. 

Perpendicular. — A line, or surface, at right 
angles to another line or surface. To drop a 
perpendicular from a given point, E (Fig. 2), 
to the line A B : From E, as a 
centre, with an opening of the 
compass greater than the dis- 
tance E D, draw the arc A B ; 
then, with the same opening, 
from the points A and B re- 
spectively, as centres, describe 
the arcs which intersect at C; 
lay your rule from E to C, and 
draw the line E D, which is 
the perpendicular wished. 

To erect a perpendicular at ihe end of the 
line A B (Fig. 3), open your 
compass to any convenient dis- 
tance, as B C, and draw th( 
arcs which intersect at D; from 
C, through D, draw a line pro- 
longed toward E, at pleasure ; 
take the distance, C D, in youi 
compass, and lay it off from D 
to E, then a line drawn from 
the point E to B, will be the 
perpendicular required. 

To draw lines parallel to each other (when 
you have no parallel ruler) : From the points 

A, B (Fig. 4), with 
an opening of 
compass equal to 
the distance desired 
for the parallel, 
C, D, then draw a line tan- 






make the arcs, 



gent to both, and you have the line C D, 
parallel to A B. 

To find a lost centre, or to find a circle which 
shall touch three given points, not in the 
same straight line : Let A, B, C (~F\<y 5), be 




the points ; set the compass in A, with an 
opening greater than half the distance from 
A to B, and describe the arc E G; then from 
B, as a centre, construct the semicircle E 
F H ; then, from C produce the arc F H. 
A straight line through the intersections of 
F H, and E G, will meet at T>, which is the 
centre of the circle in which A, B, C, lie. 

Through three points not in a straight line 
(Fig. 6), to construct a Geometric square: 




Though the point B draw the line F J ; set 
one foot of the compass in A, and draw the 
arc F G; from C, draw the arc G H; from F 
and G, draw the arcs which intersect at K, 
and from G H draw the arcs which intersect 
at L; from K, through A, draw a line, with the 
point of your compass, prolonged toward O ; 
from L draw, in the same way, the line to 
P, then with the distance from D to E, draw 
the arcs at O P, and a line tangent to them. 
Finish with ink the lines O P, P E, and O D, 
and your square is complete. 

After a few Astronomical definitions with 



42 



AMERICAN HOROLOGICAL JOURNAL. 



a view to fix in the mind the character and re- 
lations of the circles, points, lines, etc., of the 
sphere, called the "doctrine of the sphere," we 
shall plunge at once into the construction of 
dials. 

Great Circle. — The section of a sphere by a 
plane cutting it through its centre in any 
direction. Small Circles are such as are 
formed by a plane cutting the sphere in any 
direction not through the centre, dividing it 
into two unequal parts. 

Axis of a Circle. — A straight line passing 
through its centre at right angles to its plane. 

Pole of a Great Circle — Is the point where 
the axis cuts through the sphere, and is every- 
where 90° from the great circle. The earth 
is called the terrestrial sphere ; the starry 
concave of the heavens, the celestial sphere. 
The great circles of the globe, extended every 
way till they meet the heavens, become cir- 
cles of the celestial sphere. 

The Horizon. — A great circle which divides 
the earth into the upper and lower hemi- 
spheres, and separates the visible heavens 
from the invisible; this is the rational horizon 
• — the sensible horizon being the boundary of 
vision of the observer; still so vast is the dis- 
tance of the starry sphere that both these 
planes appear to cut in the same line, so 
that we see the hemisphere of stars which we 
should see if the upper half of the earth were 
removed, and we stood on the rational hori- 
zon. 

Poles of the Horizon. — The plumb line rep- 
resents the axis of the horizon — directly 
over head is Zenith, directly under our feet 
Nadir. 

Vertical Circles — Are those circles which 
pass through the poles of the horizon, and are 
perpendicular (or at right angles) to it. 

Meridian — Is the vertical circle passing 
through the north and south points. 

Altitude. — The elevation above the horizon 
measured in degrees on a vertical circle pas- 
sing through that body. 

Azimuth — Is the distance of a body from 
the meridian (measured on the horizon) to a 
vertical circle passing through it. The poles 
of the earth are the extremities of its axis, 
and when prolonged to the heavens, become 
the poles of the heavens. 

Equator. — The Great Circle cutting the 



axis of the earth at right angles. The 
intersection of the plane of the equator 
with the earth's surface, is the terrestrial 
equator, and with the concave of the heavens 
the celestial equator, and is more often called 
the equinoctial, because when the sun is on the 
equator the nights and days are equal in 
length. 

The meridians, which are always at right 
angles to the equator (or equinoctial) and 
also to the horizon, are called hour circles, 
because the arcs of the equator intercepted 
between them are used as measures of time. 

Latitude of a place is its distance from the 
equator north or south; the Polar distance is 
the angular distance from the nearest pole, and 
is the complement of the latitude. 

Longitude of a place is its distance from 
some standard meridian, east or west, 
measured on the equator. The meridian 
usualy taken as the standard is the meridian 
of the Observatory of Greenwich, near Lon- 
don. If the place be directly on the equator 
we have only to measure the arc of the equa- 
tor intercepted between the place and the 
point where the meridian of Greenwich cuts 
the equator. If the place be north or south 
of the equator its longitude is the arc of the 
equator intercepted between the meridian of 
the place and the meridian of Greenwich. 

Ecliptic is the great circle in which the earth 
performs its annual revolution around the 
sun, its plane cutting the centre of the earth 
and the centre of the sun. If the axis of the 
earth were at right angles (or perpendicular) 
to the eclij)tic, the equator would coincide 
with it ; but it is found by observation that 
the earth does not He with its axis at right 
angles to this plane, but is turned about 23|° 
out of a perpendicular direction, making an 
angle with the plane itself of 66^° — the two 
circles making an angle with each other 
of 23° 27' 43". It is very important 
to get a correct idea of these two 
circles and planes, because to them are 
referred a great number of astronomical 
measurements and phenomena, and they are 
the " ground plan" upon which the super- 
structure of dialing is constructed. 

Equinoctial Points are where these two 
circles intersect. The time when the sun 
crosses the equator (coming north) is called 



AMERICAN HOROLOGICAL JOURNAL. 



43 



the vernal equinox (about the 21st of March), 
and where it crosses the equator going south, 
the autumnal equinox (about Sept. 22). 

Sohticial Points are where the sun is most 
distant from the equator, north or south. 
The summer solstice (north) occurs the 22d 
of June; the winter solstice (south) the 22d 
of December. 

The ecliptic is divided into twelve equal 
parts, of 30° each, caUed signs, which, begin- 
ning at the vernal equinox, succeed each 
other in the following order : 



NORTHERN. 

1. Aries, T 

2. Taurus, y 

3. Gemini, H 

4. Cancer, ^ 

5. Leo, SI 

6. Virgo, TO 



SOUTHERN. 

7. Libra, *± 

8. Scorpio, Tl 

9. Sagittarius, / 

10. Capricornus, V5 

11. Aquarius, %Z 

12. Pisces, K 



WATCH AND CLOCK OIL. 

One of the most essential things in a watch 
or clock, to insure its correct performance 
and durability, is good oil. Probably every 
watchmaker has at some time learned this 
by his own sad experience, having suffered 
much in loss of time and patient labor, by the 
injurious effects of poor oil on his work. 
Hence, the importance of this subject, viz., 
oils for horological uses, to which we will give 
a brief consideration. 

After the watch or clock is carefully cleaned 
and adjusted, each of the pivots and springs 
receives its particle of oil, and the delicate 
machine is expected to keep its continuous 
motion, with almost the accuracy of the sun, 
without further attention for a year or more, 
or until it comes into the hands of the watch- 
maker again for renewed cleaning or repairs ; 
during all the intervening time the watch 
receives no more oil. It becomes then a very 
important question : What are the essential 
requisites of the oil that shall accomplish this 
result ? 

The following are undoubtedly the most 
important, viz.: 

1st. It must not corrode on metals. 
. 2d. It must not become gummy. 

3d. It must not quickly evaporate. 



4th. It must not congeal when exposed to 
severe cold. 

Equally important are the questions : How 
and where can an oil be obtained that will 
bear these four tests ? 

Is it to be found in the animal or vegetable 
kingdoms? Chemistry will do much in solv- 
ing the problem, but we shall find the most 
reliable test is experience. It is of prime im- 
portance to consider what the experience of 
practical men has been in the use of oils on 
watches and clocks. A writer in the English 
Horological Journal, vol. vii., page 74, says : 
" After a careful and protracted trial of Olive, 
Neat's-foot, Nut and Fish oils, manipulated in 
many ways, I give as the rosult of all my 
experiments, fish oil was found, all things 
considered, the best." 

In the same journal, A. Long writes : "In 
1814 and 1815, I was in the Arctic regions, 
and I remarked that train or sperm oil stood 
more cold than any other, and that a portion 
of it never congealed ; this was the oleine, 
which we preserved and applied to our 
chronometers, and thus kept them perform- 
ing through the winter." He then goes on 
to describe the process by which the oleine 
was extracted from the blubber of the whale. 
Others have written to prove that oil, ex- 
tracted from a certain kind of olive, and at a 
certain time, called Virgin oil, is best. The 
writer before mentioned says : " I first turned 
my attention to olive oil, but after a year or 
two experimenting with it I gave it up." 

All vegetable oils used on watches or 
clocks, will be found open to these serious 
objections : They will corrode on metals, and 
they will become green and gummy ho the 
pivot holes after a time. Others have tried 
mineral oils with no better success. Not to 
mention any other serious objections, they 
will be found to evaporate quickly, leaving 
the holes dry. 

Experiments have also been made with oils 
of ruminating animals, but they are found 
to contain stearine in large proportion, and 
are altogether too coarse and hard for horo- 
logical purposes. Various kinds of nut oils 
have been tried with no better success ; the 
principal objection being they corrode 
quickly. 

After all the trials and tests, by practical 



44 



AMERICAN HOROLOGICAL JOURNAL. 



men, of the various kinds of oils to find the 
kind that is best adapted to the delicate 
machinery of watches and clocks, all kinds 
but fish are found open to some objection. 
The oil obtained from the head and jaw of a 
species of the porpoise called black fish by 
the fishermen, has been used in this country 
for the last forty years or more, combining 
all the qualities mentioned above, viz. : Does 
not corrode, does not become gummy, is not 
quickly evaporated, and does not congeal in 
severe cold. The experience of practical men 
during all that time, and in various climates, 
goes to prove that the statement made above 
is correct. 

The head and jaw of the porpoise contain a 
limited quantity of the article which Mr. 
Long calls oleine, by which he probably means 
pure oil, free from all other properties. 
There is great difficulty in procuring the 
genuine porpoise oil, having to depend 
entirely upon the fishermen, who, on the sea, 
or along the shore, catch the fish and extract 
the oil ; a small part of which only can be 
safely used for horological purposes. The 
blubber should be boiled out in fresh water, 
which can be easily done when the fish are 
taken on the coast, but not so readily at sea, 
where fresh water is scarce ; therefore it 
becomes important that the oil should be 
chemically tested, for if salt is detected it 
becomes positively injurious when applied to 
the watch. It must also be sweet ; if it has 
become changed, acids are generated which 
make it injurious. After being sure that the 
oil is good and of the right kind, it is only by 
a tedious course of preparation that the 
crude oil can be put into a condition to stand 
the fom* tests spoken of. 

A very effectual test of good oil may be 
made by countersinking a small cup on any 
old watch plate deep enough to hold a drop; 
fill it with the oil and set it aside, covered 
with a glass so that no dust may get to it ; if 
it remains clear and liinpid ten or twelve 
months, three of the essential points are set- 
tled. The other point is easily proved by 
subjecting it to a very low temperature. 
Manufacturers on the continent and in Eng- 
land, very generally use olive oil on their 
watches, and on arrival here the oil is usually 
found to be thick and gummy, rendering it 



necessary to clean the watch and put on fresh 
oil before it is safe to warrant it to perform 
correctly. 

They are beginning to appreciate the great 
advantage which fish oil has over the vegeta- 
ble and other kinds for horological purposes, 
and already there is a large market for Amer- 
ican oils among manufacturers, and the de- 
mand is constantly increasing. 

A change for the better is apparent when 
the porpoise oil is used on imported move- 
ments ; they move more freely and are in 
much better order for the pocket on their ar- 
rival here, and can be relied upon more surely 
from the start. In Paris clocks especially, 
the pivots are clean and free, instead of the 
green and gummy state in which they have 
usually been found. No oil will keep good in 
close proximity with cedar wood; if this wood 
is used in any part of a clock case, the oil will 
become gummy in a short time. A like result 
will be produced on watches kept in drawers 
made of cedar. 

In conclusion, it appears that the oil of the 
porpoise or black fish has proved by long ex- 
perience as well as by chemical tests, to be a 
good oil for clocks and watches. Further 
investigation may bring to light something 
better, but until that time arrives, the trade 
will undoubtedly use it in the future as it has 
in the past. 

Our patrons, after reading this article, may 
ask us, who are the manufacturers who put 
up this oil which has been found in practical 
workings to be the best ? In answer, we know 
of none better than the oil put up by I. M. 
Batchelder, of which Palmer, Batchelders & 
Co., 162 Washington street, Boston, are sole 
agents. It is well known throughout this 
country and is extensively used in London, 
Paris, and among the manufacturers of Eng- 
land, France, and Switzerland. 



SOFT SOLDElt. 



Stepping into the shop of a jeweller friend 
a few days since, I found him putting the stem 
on to a gilt watch case with soft solder. I 
remonstrated with him, but he said it was 
his orders. '"You see," said he, "if I hard 
solder it, it will discolor, and will have to be 



AMERICAN HOROLOGICAL JOURNAL. 



45 



re-gilt." He kept on, and after three attempts 
he made it stick until I got away, and if he 
sent it home done up in cotton, I have no 
doubt it arrived safe. 

Now we have had two commandments 
given us. The first is, " Never soft solder a 
job that can by any possibility be hard sol- 
dered;" and the second is like unto it, 
'•'Never use soft solder on any article of gold 
or silver that may by chance require to be 
hard soldered afterward." On these two 
commandments hang all the tinkers' law and 
profits. 

But it is necessary at times to use soft sol- 
der, and I am going to tell you how I do it, 
having no doubt at the same time that all of 
my readers can do it better than I can. 

Since the good old resinous days have gone 
by, we have come to the use of soldering 
fluid, or a fluid that when dried off by heat 
will leave a coating on the article to which 
the solder will readily adhere, and also a flux 
to assist it in the flow. 

To make this fluid, I put, say one pound of 
muriatic acid in a glass jar, set it out in the 
open air, and add to it some pieces of clean 
zinc. "When the violent ebullitions have ceased 
I add more zinc than the acid can possibly 
take up. I let this stand for several hours, 
then add about half a gill of water, when it 
will commence eating again. I let this stand 
again, then add a little water, and continue 
this so long as I can discern any signs of 
action on the zinc. I stir it well with a stick 
each time I add water, and if, after standing, 
I tap the jar and no bubbles rise, I consider 
it has ceased action. Then I add one ounce 
of sal ammonia, let it stand over night, pour 
off the clear fluid, and throw away the sedi- 
ment. It should be kept corked, as the 
strength of the acid is quite exhausted, and 
when steel is soldered with it, if washed off 
with alcohol, there is very little fear of its 
rusting afterward. 

The best solder I have ever used, I have 
bought from the britannia workers. It keeps 
for a long time without tarnishing, and is far 
superior in every respect to the rolled solder 
found at the material dealers. Clean the parts 
well, and do not apply heat enough to start 
the temper of brass, silver, gold or steel. 

D. W. B. 



WATCH CLEANING. 



Old Shirts are indispensable to the watch- 
maker — in fact they are invaluable. Let 
no one, however urgent his pecuniary neces- 
sity, ever yield to the temptation of selling one 
to the ragman in order to " raise the wind," 
neither let your washwoman so work upon 
your sympathetic generosity as to beguile you 
out of one, on the specious plea that "she 
can cut it down for the baby." They are good 
for something — -don't you, for a moment, listen 
to the hackneyed expression that they are of 
no further use to you ; they are useful, nay 
more, they are precious. 

Of course we would not have you imagine 
that new shirts were not also proper, and ne- 
cessary, and convenient. But new ones you 
can dispense with. By the aid of " modern 
improvements '' you can " make shift " to do 
without them ; the thousand and one recent 
appliances of paper have almost made the 
shirt obsolete. With a paper dickey, and a 
paper collar, and a paper tie, and paper cuffs, 
its absence is rarely noticed ; in fact, the 
difference between the uses of the new and 
the old is, that the former is used to conceal 
dirt, and the latter to remove it. 

Several of our correspondents have made 
mention of their various modes for cleaning 
watches by brushings, and washings, etc., all 
very good in their way; but our own plan we 
like best of all yet tried. Every one knows 
(or ought to know) the tender nature of 
cheap gilding, and its liability to removal by 
the slighest abrasion, and with brushing the 
corners off, all the cocks and bridges get the 
most of it. All the under parts, where dirt 
" most does congregate," we brush with al- 
cohol, and a little chalk if necessary ; all the 
upper gilded parts we wash with a camel hair 
pencil dipped in alcohol, and wipe dry with 
well worn cotton or linen cloth, which cleans 
them perfectly, produces not the least scratch, 
leaves the work as bright as when originally 
finished, and we are persuaded that when 
once tried it will not be abandoned. Of course, 
when the brash is used the cloth must not be, 
for the fibre brushes up and lint is apt to get 
on the parts ; but when used simply as a 
wiper all the fibres are easily removed by a 
puff of the breath. 



46 



AMERICAN HOROLOGICAL JOURNAL. 



New fabric must never be so used, as it is 
filled with starch, which renders it harsh. 
Cat up the cloth in squares of about four 
inches, packed away carefully in a box or 
drawer from dust. If judiciously used there 
is nothing that we have ever tried that so well 
answers the purpose. 



ANSWERS TO CORRESPONDENTS. 

G. F. E., Memphis, Tenn — There are, as you 
suggest, other and larger Catalogues of Stars, 
such as what is known as " The Greenwich 
Twelve Year Catalogue," a list of 2,156 stars ; 
" The Catalogue of the British Association for 
the Advancement of Science," containing the 
positions of 8,377 fixed stars, and others. As 
they are not published annually, but only at 
long intervals, their use requires the employ- 
ment of tedious and difficult formulae to cor- 
rect the positions of the stars for any required 
date ; hence the use of these Catalogues is 
confined principally to the great Observa- 
tories. 

We doubt whether either of those men- 
tioned can be obtained short of importation 
from London, but we presume any of the 
chronometer and nautical instrument dealers 
would import them to order, that business 
being somewhat in their line. Address John 
Bliss & Co., No. 66 South street, N. Y. 

As to the adjustment of a transit, aided by 
the observation of stars passing the meridian 
at different degrees of declination, no better 
method can be devised. For this purpose 
preference is given to those which pass the 
meridian at or near the zenith, and those of 
low declination. When the axis of the instru- 
ment is accurately levelled, its telescope 
describes a vertical circle, of course, passing 
through the zenith, whatever may be the 
position of the transit. Therefore, if the 
telescope be placed approximately in the 
meridian, and a star be selected that passes 
through the zenith, its observed meridian 
passage will not be affected by the azimuthal 
error of the instrument, and consequently 
the true time may be obtained. If, now, a 
star of low declination be observed to cross 
the lines of the transit, the difference between 



the calculated and the observed time of tran- 
sit shows the amount of azimuthal error due 
to that declination, and the frame of the tran- 
sit must be turned in that direction, east or 
west, which will lessen this error. When, by 
repeated trials, the high and low stars show 
the same amount of error in the time-piece 
used, allowance being made for its rate, if 
any, the transit is proved to be in adjust- 
ment. 

The method by the Pole Star, used by 
some, while fully as accurate as any, has the 
advantage of being easily adapted to the 
wants of the unskilled. The slow motion of 
the Pole Star is what makes it of value in this 
connection, as the centre, or meridian line, 
may be readiry adjusted on the star, when on 
the meridian, small errors in the time-piece 
used, or slight inaccuracies in the manipula- 
tion, affecting the result to a trifling extent 
only ; while a few repetitions of observa- 
tions of the sun, followed by corrections of 
the correspondence of the meridian line and 
the star at its culmination, serve to entirely 
eliminate any error in azimuth. 

H. H., Murphysboro, III. — I am pleased to 
answer the query, inasmuch as it affords me 
an opportunity of pointing out an advantage 
in the method of developing the escapement, 
as illustrated and described by Fig. 1, in my 
article on Chronometer Escaj)ement, in July 
number. If the gentleman will please take 
up and examine the description of the draw- 
ing again, he will see that it is from a given 
centre distance, which he calls depth, that the 
relative diameters of wheel and roller are de- 
veloped with a view of obtaining a certain 
amount of leverage impulse ; and hence it is 
possible, according to this method, to deter- 
mine and fix the centre distance in the watch 
before either wheel or roller is made. If, then, 
an escapement were constructed on this prin- 
ciple, an error of depthing could not oecr", 
except the wheel and roller were made of 
other diameters than obtained in the devel- 
opment, which could only be attributed to 
gross neglect on the part of the workman. 
Different is it according to another mode of 
constructing the escapement, where from a 
given diameter of wheel the relative size of 
roller is determined, and the centre distance 
afterwards pitched with the finished roller and 



AMERICAN HOROLOGICAL JOURNAL. 



47 



•wheel. In this case an error of depth could 
easier take place, though it will be found as a 
rare occurrence. Should such be the case, it 
■will be easily remedied by making the diame- 
ter of the roller either smaller or larger, as 
the case may require; and to do this, it would 
be only necessary to move the impulse jewel 
a little further out or in. This will remedy 
the fault, though the amount of leverage will 
be changed a little ; but as the diameter of a 
finished wheel cannot be made other than it 
is except by a new one, this could not be 
avoided. Th. Gribi. 

A.W., Stamford, Ct. — There must be some 
fault in the method of using the pickle which 
we cannot discover. Did you heat the jew- 
elry nearly or quite red hot and plunge it in 
the pickle ? or was it not possible the articles 
you experimented on were silver plated ? if so, 
there is no restoring it except by replating. 
The plan will certainly and successfully work 
on solid silver goods, for we have used it for 
years, and we can scarcely believe that a 
pickle of 2 parts sulphuric acid and 1 part 
nitric diluted with water (as directed) till it is 
only very sour to the taste, will in the least 
injure silver, even if it were to remain in it 48 
hours. 

Key pipes or tubes are drilled to a little 
more than the proper depth; then a perfectly 
square punch, the face of w T hich is exactly at 
right angles to the axis of the punch, is driven 
to the bottom, forcing before it the amount of 
metal shaved off in squaring up the round 
hole ; it is then finished off outside — hard- 
ened and tempered, if it is intended to be a 
good, key pipe. 

Mr. English, of Springfield, Mass., makes 
an excellent patent steel key, both for the 
pocket and the bench. Most of the keys and 
key pipes in use are made abroad. 

C. W. H., North Adams, Mass. — Do you 
mean the hole through a new pinion, as they 
come from the material dealer? If so, the 
best way for you to fit the hole to the arbor 
of the old square, is to make a " rose drill " of 
the exact size of the smallest diameter of the 
square arbor where it comes through the 
pinion under the dial. 

The " rose drill " is made from a piece of 



steel wire fitted to your drill stock, or what is 
better, in the chuck of an American lathe. 
Tarn down the end of the wire for about the 
16th of an inch to the exact size you wish the 
hole through the pinion ; above that turn 
down a shank, a little smaller, only to give 
perfect freedom; but not enough to weaken 
the drill; then round off the end nicely to a 
half-round or less, and file the rounded end 
into a series of radial grooves, all brought to 
cutting edges; then harden and temper, and 
you will have a drill which will surely follow 
the hole you wish to open. Be careful to 
have the straight part of the drill no larger 
behind than at the end, otherwise it will bind. 
This drill will not deviate from the centre of 
the hole it follows, for the smooth sides form 
a perfect guide. 

To give the hole the requisite taper to fit 
the arbor, a very little opening with a |- brooch 
(holding the pinion in the fingers) will be 
sufficient. 

E. C. B., Newport, R. Z— The "Turns" you 
inquire about are nothing more than the 
ordinary steel bench lathe, which every watch 
maker has, and they are often spoken of as 
dead centre lathes, to distinguish them from 
those which run with a band and have a live 
centre. 

R. H. L., Spring Lake, Mich. — "With a dia- 
mond point, or the sharp corner of a piece of 
steel, as hard as fire and water will make it, 
mark -the spot on the glass where the hole is 
desired. It must be sufficiently deep to hold 
from slipping the end of a copper wire, which 
must be charged with emery (about No. 60) 
and water. The size of emery will depend 
somewhat on the size of hole you wish ; for 
a small hole coarse emery will not stay with 
your drill ; you can run the drill by a drill- 
stock and bow, or by a lathe. Glass differs 
very much in hardness, depending upon its 
composition ; some being very difficult to 
drill nicely, except with No. 1 diamond dust. 
The hole, when through, can be enlarged at 
pleasure, by using a copper wire, sharpened 
at such an obtuse angle as not to bind in the 
hole, and charged with emery the same as for 
drilling. To prevent chipping, work from 
each side of the glass alternately. The most 
expeditious way is with a diamond drill, 
which is not always at hand. 



48 



AMERICAN HOROLOGICAL JOURNAL, 



J. M. L., South Paris, Me. — The method of 
measuring clock pendulums, so as to get the 
right length when they are lost or broken, is: 
First find the number of revolutions or parts 
of a revolution the scape wheel makes in a 
minute ; multiply the number of revolutions 
or parts of a revolution by twice the number 
of teeth that there is in the scape wheel, 
which will give the number of vibrations the 
desired pendulum will have to make in a 
minute ; then divide the number, 141,120.0 
by the square of the number of vibrations, 
and the product will be the length of the pen- 
dulum in inches. 

J. B. M., Cincinnati, 0. — Mr. Herrmann, our 
London correspondent, is a German by birth, 
about thirty years of age, and has been a resi- 
dent of London some eight or ten years. He 
is both a practical workman and a scientific 
horologist. For three years past he has been 
the instructor of the Drawing Class in the 
British Horological Institute, a position for 
which he is well qualified, possessing a degree 
of patience that is so necessary in a teacher. 
In the October number we expect to present 
to our readers a scientific article from him, on 
the construction of an epicycloidal shaped 
tooth of an} 7 size, by the method of co-ordi- 
nates. 



AMERICAN HOROLOGICAL JOURNAL, 

PUBLISHED MONTHLY BY 

G-_ LB , MILLER, 

2 29 Broadway, X. Y., 
At $ - 2.-50 per Year, payable iu advance. 

A limited number of Advertisements connected 
with the Trade, and from reliable Houses, will be 
received. 

TERMS OF ADVERTISING. 

Inside pages 20 cents per line. 

Pacing reading matter 25 " 

Outside pages 30 " 

Oae colurau $15 

Half column 8 

Special rates per page according to location. 
Ten words average a line. 

J0^° Mb. J. Herrmann, 21 Northampton 
Square, E. C, London, is our authorized Agent 
for Great Britain. 

All communications should be addressed, 

G. B. MILLER, 
P. 0. Box 6115, New York. 



EQUATION OF TIME TABLE. 



GREENWICH MEAN TIME. 









For August, 1870. 






© 

© 




Sidereal 
Time 


Equation 
of 


Equation 




Sidereal 


© 


Day 
of 
vlon. 


of 
the Semi- 
diameter 


Time to be 

Added to 

^uut. acted 


Time to be 
Subtracted 


Dim 
for 
One 


Time 

or 
Right 


O 
=! 

c 


Passing 

the 
Meridian. 


from 

Apparent 

Time. 


Added to 

Mean Time. 


Hour. 


Ascension 

of 
Mean Sun. 






s. 


M s. 


M. s. ! S. 


H. M. s. 


M.. 


1 


66.64 


6 4.33 


6 4.35 ■ 0.143 


8 39 34.09 


Tu. 


2 


66 56 


6 0.58 


6 0.60 ' 0.169 


8 43 30.65 


W 


3 


66.47 


5 56 21 


5 56.23 0.195 


8 47 27.20 


Th. 


4 


66 39 


5 51.21 


5 51.23 | 0.222 


8 51 23.76 


Fri 


5 


66.30 


5 45 59 


5 45 62 , 0.248 


8 55 20.31 


Sat- 


6 


66.22 


5 39.36 


5 39.39 0.273 


8 59 16.87 


Sii. 


7 


66 13 


5 32.53 


5 32.56 0.298 


9 3 13.42 


M.. 


8 


66 05 


5 25.09 


5 25 12 


0.323 


9 7 9.98 


Tu. 


9 


65 96 


5 17.06 


5 17.09 


0.348 


9 11 6.53 


W. 


10 


65.88 


5 8.43 


5 8.46 


0.372 


9 15 3.09 


Th. 


11 


65.79 


4 59.23 


4 59.27 


0.396 


9 18 59.64 


Fri. 


12 


65.71 


4 49 47 


4 49.50 


0.419 


9 22 56.20 


Sat. 


13 


65 63 


4 39.16 


4 39.19 


0.442 


9 26 52.75 


Sii. 


14 


65.55 


4 28.30 


4 28.32 


0.464 


9 30 49.31 


M.. 


15 


65.47 


4 16 91 


4 16.94 


0.486 


9 34 45.86 


Tu. 


16 


65.40 


4 5.01 


4 5.04 


0.507 


9 38 42.42 


W 


17 


65.32 


3 52.60 


3 52.64 


0.528 


9 42 38.97 


Th 


18 


65 25 


3 39.70 


3 39.73 


0.548 


9 46 35.53 


Fri 


19 


65 . 17 


3 26.32 


3 26 35 


0.568 


9 50 32.08 


Sat 


20 


65.10 


3 12.48 


3 12.51 


0.587 


9 54 28.63 


Sii. 


21 


65 03 


2 58.18 


2 58 21 


606 


9 58 25.19 


M.. 


22 


64.97 


2 43 43 


2 43 47 


0.624 


10 2 21.74 


Tn. 


23 


64.90 


2 28 25 


2 28.28 


0.642 


10 6 18.30 


W. 


24 


64 84 


2 12.65 


2 12.68 


0.660 


10 10 14.85 


Th 


25 


64 78 


1 56.63 


1 56 66 


0.677 


10 14 11.40 


Fri 


26 


64 72 


1 40.21 


1 40.23 


0.694 


10 18 7.96 


Sat. 


27 


64.66 


1 23.40 


1 23.42 


0.710 


10 22 4.51 


Su 


28 


64.61 


1 6 21 


1 6 24 


0.726 


10 26 1.06 


M. 


29 


64.55 


48 66 


48 67 


0.741 


10 29 57.62 


Tu. 


30 


64 50 


30.75 


30 75 


0.755 


10 33 54.17 


W. 


31 


64 45 


12.49 


12.49 


0.769 


10 37 50.72 















Mean time or the Semidiameter passing may be found by sub- 
tracting 0.18 s. from the sidereal time. 

The Semidiameter for mean neon may be assumed the same a3 
that for apparent noon. 

PHASES OF THE MOON. 

D. H. M. 

) First Quarter 3 20 51 . 5 

© Full Moon 10 2113.5 

( Last Quarter 18 19 50.4 

© New Moon 26 9 25.6 

D. II. 

i Perigee 3 2.1 

( Apogee 17 12.6 

( Perigee 29 10.3 

O / // 

Latitude of Harvard Observatory 42 22 48 . 1 

h. M. s. 

Long. Harvard Observatory 4 44 29 . 05 

New York City Hall 4 56 0.15 

Savannah Exchange 5 24 20 572 

Hudson, Ohio _ 5 25 43.20 

Cincinnati Observatory 5 37 58 . 062 

Point Conception 8 142.64 

APPARENT APPARENT MERID. 

R. ASCENSION. DECLINATION. PASSAGE. 

D. H. M. S. o < , H. M. 

Venus 1 6 29 20.43.... +22 26 38.2 2150.9 

Jupiter.... 1 5 10 32.98.... 22 23 23.9 20 28.4 

Saturn. .. 1 17 27 17.33. ... -22 4 2.1 8 46.2 



AMERICAN 




Journa 



Vol. II. 



NEW TORE, SEPTEMBER, 18 70 



No. 



CONTENTS. 

How c\:s the Condition of the Coming Workman 

be Improved ? 49 

Heat, 51 

Dialing, 55 

Adjustment to Temperature and Position, . . 58 

•Jewelling, 59 

John Bliss & Co.'s Improved Transit Instrument, 61 

Pinion Measurement, 62 

Ortho-Chronography, 63 

New Staking Tool, 64 

Jean Paul Garnifr, 64 

Industrial Exposition ln Altona, 67 

Trifles, 68 

Answers to Correspondents, 68 

Equation of Time Table, 72 

* * * Address all communications for Horological 
Journal to G. B. Miller, P. 0. Box 6715, New York 
City. Publication Office 229 Broadway, Boom 19. 

HOW CAN THE CONDITION OF THE COMING 
WORKMAN BE IMPROVED? 



Since we have been the vehicle of inter- 
communication between our fellow-craftsmen 
we have been in constant receipt of letters 
and communications setting forth innumera- 
ble hopes, and fears, and grievances connected 
with the trade. By these interchanges intel- 
ligent, energetic, well-read, well-educated 
men have come to light, and have bid us be 
of good cheer, and have upheld our hands on 
either side, like the friends of the prophet of 
old. And then again there bave been 
developed another class — restless, progressive 
enthusiasts, such as infest all communities, 
and all occupations ; men whose zeal, were 
it modified by discreet knowledge, would be 
most able helpers in any cause. We have 
also encountered the usual number of misan- 
thropic grumblers, who are dissatisfied with 
others, and equally so with themselves. 
Taking the views of the whole together as a 
unit, we have found a most decided want of 
unanimity among the trade ; scarcely any 
considerable numbers entertaining the same 
view of the condition of things ; and the ideas 
regarding the betterment of our condition 
are equally various. Many are anxious to 
establish a Trade Union, for the mutual pro- 



tection of the interests common to all — for 
the establishment of prices — for the defence 
of the skilful mechanic against the predatory 
incursions of the ignorant " hangers-on." 
Others desire something like a Board of 
Equalization, with power to decide upon the 
merits of various grades of workmen, and to 
award diplomas of merit, which shall be a 
guarantee to the incredulous community of 
the character of the bearer. In fact there is 
no end to the devices which each orse wants 
adopted and enforced against his neighbor. 

Not as authoritative, nor with the idea of 
propounding any plan better than any one 
else, but simply to develop thought that may 
ultimately assume form and proportion, we 
will state a few objections to some of the plans 
mentioned. Trades Union is a subject which 
is claiming the attention of the best minds of 
the country, and the discussions, pro and con, 
are familiar to all ; and it would be egotisti- 
cal presumption for us to claim new light on 
the subject. The organization of a society or 
class of workmen who consider themselves 
the best, or that may be considered so by 
others, arrogating to themselves, or even 
receiving authority (delegated) from others, 
to decide upon the merits of a workman, and 
to enforce that decision by any pains and 
penalties, we consider futile, and confess our 
lack of ability to see what good can come of 
it. "We think we can see in it evil, and only 
evil continually. The favored few — the aris- 
tocrats of the trade— will be the minority 
and must necessarily encounter the uncom- 
pro nising hostility of the majority — the out- 
casts from the "society "- — -and we well know 
how powerless minorities are in a free country. 
Graded classes, we think, would meet with 
no better success. No workman would like 
to hang up his diploma as a second or third 
class workman ; he would rather cast his lot 
with " outsiders," and trust to his own tact 
to make his way to & first-class notoriety with 



50 



AMERICAN HOROLOGICAL JOURNAL. 



the community, and snap his fingers at the 
"society's" diploma. To decide upon the 
merits of a workman would require the knowl- 
edge of a god ; to establish any system of 
test rules would be next to impossible. A 
good finisher might be a very poor workman, 
and a first-class workman be a very poor 
finisher. The possibility of being first-class 
in some specialty makes it positively impos- 
sible to say who is first-class. 

If any such ideas should ever become crys- 
tallized into form, our conception is, that 
Principles should be the measure of a man's 
knowledge — not moral principles, but the 
known and well-established laws of nature in 
every department of science that bears rela- 
tion to a man's chosen profession. There can 
scarcely be a possibility that a person so in- 
formed, so learned, we may say, can ever 
make any great mistake in the practice of his 
art or calling — which is but the embodiment 
of those fixed laws. As a familiar illustration 
of our idea, suppose a watchmaker who knows 
the principles of correct depthing, was called 
upon to correct some fault in a watch; would 
he ever alter the proper relation of wheel 
and pinion to remedy a fault which he abso- 
lutely knew could not exist there ? He would 
of course look elsewhere for the error. Or 
would a watchmaker who knew the laws per- 
taining to springs, under all ordinary or 
extraordinary conditions, be guilty of rivet- 
ing together the broken ends of a main- 
spring in a fine watch ? He more likely would 
endeavor to explain to the owner the utter 
impossibility of such a method of repair ever 
proving satisfactory, and perhaps show him 
the reason why ; then, if the owner, through 
cupidity or stupidity, insisted on its being so 
done — that it would do for the present, etc. 
— that watchmaker would, if possessed of 
any professional pride, advise him to take it 
to some craftsman who had no reputation to 
lose by such work. If the owner was a sen- 
sible man he would say, do it as it should be 
done ; if he proved to be otherwise, the 
sooner the two part company the better. 

We conceive it to be far more important 
to be thoroughly educated in primary prin- 
ciples than in handicraft. The former are 
comparatively few, easily and quickly learned, 
and are immutable ; while art-skill in manipu- 



lation is endless ; the duration of a whole life 
being insufficient to acquire the ten thousand 
ways of doing a thing when only one principle 
is involved. Primary laws being the same 
for all, their application is infinite, and affords 
free scope for the endless diversity of taste, 
and full development of individuality. And 
however multiplied the forms which adapt 
themselves to the laws, there is no danger of 
failure in the ultimate performance of such 
constructions, because all the endless modi- 
fications of form are continually subservient 
to, and under the control of, and in conform- 
ity with, immutable laws. We are pleased 
with remarks we find in a series of articles 
on Applied Mechanics, published in the Brit- 
ish Horological Journal: "It seems to me 
that in our mechanical teaching we make too 
much of mechanism, which may be varied 
indefinitely, and too little of natural prin- 
ciples. The consequence is that by far too 
much we copy each other's arrangements of 
mechanism ; whereas, if we were taught the 
natural and mathematical principles, and 
showed that they could be applied in many 
different ways, setting each one to find his 
own mechanism, and letting it be considered 
wrong for a man to copy other men's me- 
chanical forms and arrangements, within a 
reasonable period, by so doing, a great change 
would soon be experienced, if our young men 
were sent out to explore in the boundless 
field of mechanism, which lies open to all, 
instead of repeating the forms and arrange- 
ments which have been adopted by others." 

* * * * " The prominent consideration 
of the natural principles as thus associated 
with and determining working mechanism, 
would impart a dignity to mechanical art." 

* * * « There is no sound practice with- 
out true principles, come from where they 
may ; and practical men are immensely in- 
debted to those philosophers and men of 
science who frequently and without remunera- 
tion take the trouble to investigate first 
principles, and give them to the world freely 
and fully, whose labors have been and are 
now of incalculable value in reducing facts to 
order, and giving us simple yet comprehen- 
sive formulas for the guidance of construction, 
and who investigate and lay open the mys- 
terious laws of heat, and other natural 



AMERICAN HOROLOGICAL JOURNAL. 



agencies, and make plain to the more occu- 
pied and plodding busy -workers, the wonder- 
ful phenomena of the innumerable laws of 
nature." 

Technological education we think has some- 
what the same relation to art that the (dements 
of penmanship have to the beautiful art 
itself. A few up and down strokes, a few 
concave and convex hues, once fixed in the 
memory, and there is no end to the elabora- 
tion of them into elegant, graceful, charming 
forms. We, of course, do not expect to 
change the present condition of things, nor 
very materially change the views of the work- 
ing men who now fill their various positions, 
more or less to the satisfaction of themselves 
and the community where they operate. But 
we do hope to initiate a reform in the future 
education of the young who are to fill our 
places, and upon whose education will depend, 
not only the practice, but the science of Horol- 
ogy. We also fancy that we discern, in the 
dim future, an endless multiplicity of manu- 
facturing industries, directly connected with 
our art, springing up in all parts of our vast 
domain — the products of which must eventu- 
ally supply the ceaseless demands of our 
growing country ; and we should feel a na- 
tional pride in knowing that all the watch 
manufactories to come were compelled, by 
the educated opinion of the trade, to con- 
struct their products, however diversified in 
form, upon truly philosophical and mathe- 
matical principles, and we feel that this can 
be done. Our factories have commenced the 
good work, and have made creditable prog- 
ress in the right direction. "We all know 
that our machine-made watches, although far 
inferior to many foreign in final finish, will 
compare more than favorably in performance 
with them. Take the extreme grades of the 
American Watch Company, for illustration of 
our idea. The " Home," the lowest and 
cheapest variety, as compared with the " Am- 
erican Watch Co.," the highest grade, is 
of the rudest construction ; no pains taken 
in any part of its manufacture, and yet the 
disparity of performance in the two classes is 
by no means proportionate to the difference 
in price. This occurs from the fact that the 
caliper of each is the same, all parts being 
mado to gauge; ihesama principles are adhered 



to in the construction of each, and conse- 
quently the perfection of performance is only 
the result of perfection of finish. Therefore 
we indulge the hope that the principles upon 
which the Coming Factories will operate 
shall be correct. We ought surely to profit 
by past experience, having suffered enough 
from the shower of " hap-hazard " productions 
of the Old World that have rained upon 
us, to take warning, and not copy blindly 
their errors. We know that " to err is hu- 
man," but to perpetuate a mistake, plainly 
seen to be such, is " infernal stupidity ; " and 
in view of the coming factories, the coming 
workmen, and the coming population, let us 
cast about us for the best, most expeditious, 
and most effective mode of education. 



HEAT. 



NUMBER TWO. 



SOURCES OF HEAT — THE SUN'S RAYS COMBUSTION 

CHEMICAL MIXTURE — THE ELECTRIC AND GAL- 
VANIC DISCHARGE, ETC. 

Having in our last number glanced at the 
nature of heat, Ave will now proceed to look 
into the sources from whence it is derived ; 
the most important being the rays of the sun, 
combustion, percussion, friction,chemical mix- 
ture, and the electric and galvanic discharge. 

The great source of heat to our world, and 
probably the rest of the solar system, is the 
radiant caloric that is projected from the sun. 
Heat from this source has been approximately 
estimated by Pouillet as being between 2662° 
and 3202° Fahr. When a sufficient number 
of rays are concentrated on one spot, either 
by concave mirrors or convex lenses, the most 
powerful heat is excited. When the Romans 
were besieging Syracuse, 213 B. C, Archi- 
medes is said to have used a number of me- 
tallic mirrors with such effect as to set fire to 
their fleet. The experiment has been repeated 
in modern times. Buffon arranged 168 small 
plane mirrors in such a manner as to reflect 
radiant light and heat to'the same focus, like 
one large concave mirror. With this appara- 
tus he was able to set wood on fire at the 
distance of 209 feet, to melt lead at 100 feet, 
and silver at 50 feet. The following effects 



52 



AMERICAN HOROLOGICAL JOURNAL. 



were produced by a large lens or burning 
glass, two feet in diameter, and made at 
Leipsic in 1691 : Pieces of lead and tin were 
instantly melted ; a plate of iron was soon 
rendered red hot, and afterwards fused or 
melted ; and a burned brick was converted 
into a yellow glass. A double convex lens, three 
feet in diameter and weighing 212 lbs., made 
by Mr. Parker, of England, melted the most 
refractory substances. Cornelian was fused 
in 75 seconds ; a crystal pebble in 6 seconds, 
and a piece of white agate in 30 seconds. 
This lens was presented by the King of Eng- 
land to the Emperor of China. It would ap- 
pear from an experiment of Rumford's, that 
the great heat excited in these cases depends 
entirely on the concentration of the rays, and 
not from any change in their nature, because 
when he directed a portion of the rays against 
a substance adapted for absorbing them, the 
total amount of heat communicated to it was 
the same, whether the rays were received on 
the surface in a diffused state or brought into 
a small focus. What the sun is composed of, 
that it has for thousands of years poured forth 
undiminished supplies of heat, astronomers 
cannot determine. It has long been supposed 
to be in a state of violent combustion, but the 
various observations of Dr. Herschel and 
others render it probable that this notion is 
erroneous. From them it appears that the 
sun is an opaque globe, surrounded by an 
atmosphere of great density and extent ; in 
this atmosphere there are two regions of 
clouds; the lowermost of the two are opaque, 
and similar to the clouds that form in our 
own atmosphere ; but the higher region of 
clouds are luminous, and emit the immense 
quantity of light to which the splendor of the 
sun is owing. The sun is supposed by some 
to emit three kinds of rays : the calorific, 
colorific, and deoxidizing. The first occasions 
heat, the second color, and the third separates 
oxygen from various bodies. Captain John 
Ericsson, the inventor of the caloric engine 
and the monitor system of naval warfare, has 
for some time past been engaged on a series 
of experiments having in view the utilizing 
the heat of the sun for mechanical purposes. 
Probably we may be able to give the result of 
a number of his experiments in a future num- 
ber. 



The most important sources of heat which 
we have in our power to supply at pleasure, 
is that which depends on combustion ; and 
few phenomena are more wonderful and inter- 
esting. When a stone or a brick is heated, 
they undergo no change ; and when left to 
themselves they soon cool again, and become 
as at first ; but when combustible bodies are 
heated to a certain degree in open air they 
suddenly become hotter of themselves, con- 
tinue for a time intensely hot, and send out a 
copious stream of light and heat. When this 
ceases, the combustible matter has undergone 
a most complete change, being converted into 
a substance possessed of very different prop- 
erties, and no longer capable of combustion. 

All bodies, so far as combustion is con- 
cerned, may be divided into supporter?;, com- 
bustibles, and incombustibles. By supporters 
are meant certain bodies, not indeed capable 
of burning, but combustion cannot go on 
without their presence. Air, for example, is 
a supporter. Combustibles and incombus- 
tibles require no explanation. The following 
are all the supporters at present known : 
Oxygen, chlorine, air, nitrous oxide, nitrous 
gas, nitric acid, and euchloric gas. The 
combustibles are either the simple substances 
which have already been described, or com- 
binations of these with each other, or with 
oxygen without combustion ; in which last 
case they may be called combustible oxides. 
During combustion the oxygen or chlorine of 
the supporter always combines with the com- 
bustible, and forms with it a new substance, 
which may be called a product of combustion. 
Now every product is either, 1st, water ; 2d, 
an acid ; or 3d, a metallic oxide. Some prod- 
ucts are capable of combining with an addi- 
tional amount of oxygen; but this combination 
is never attended with combustion, and the 
product, in consequence, is converted into a 
supporter. Such compounds may be called 
partial supporters, as a part only of the oxygen 
which they contain is capable of supporting 
combustion. Since oxygen is capable of sup- 
porting combustion only in the supporters 
and partial supporters, it is clear that it is in 
a different state in these bodies from what it 
is in products. It is probable that in sup- 
porters it contains, combined with it, a con- 
siderable quantity of heat, which is wanting 



AMERICAN HOROLOGICAL JOURNAL. 



53 



in products. It is also probable that com- 
bustible bodies contain light as a constituent, 
for the quantity of light emitted during com- 
bustion depends on the combustible; while the 
heat seems, in some measure at least, to depend 
on the oxygen. If these two suppositions 
be admitted, the phenomena of combustion 
admit of an easy explanation : the base of the 
oxygen and of the combustible combine to- 
gether and form the product ; while the heat 
of the one and the light of the other in like 
manner unite and fly off in the form of fire. 

It is well known that heat is produced by 
the percussion of hard bodies against each 
other. Iron may be heated red hot by strik- 
ing it with a hammer, and the sparks emitted 
by flint and steel are well known. This evo- 
lution of heat appears to be the consequence 
of the permanent or temporary condensation 
of the bodies struck. Iron, and most metals, 
become specifically heavier when hammered, 
and condensation alwaysevolves heat. When 
air is condensed it gives out a considerable 
quantity of heat — sufficient to set fire to tinder. 
When muriatic acid gas is passed through 
water it is condensed, and the water becomes 
hot ; on the other hand, when air is rarefied 
it suddenly becomes much colder. It is not 
difficult to see why condensation evolves heat. 
The particles being forced nearer each other, 
the repulsive force of the heat is increased, 
and a portion, in consequence, is driven off. 
The specific caloric can scarcely be conceived 
to diminish without the body giving out heat. 
A part of the heat which follows percus- 
sion is often owing to another cause. By 
percussion, the heat of the body is raised so 
high that combustion commences, and this 
occasions a still farther increase of heat. It 
is in this way that sparks are produced when 
flint and steel are struck ; the sparks being 
small pieces of steel which have taken fire 
and melted during their passage through the 
air. 

Heat is not only evolved by percussion, 
but also by friction ; and not only by friction 
of hard bodies, but even of soft bodies, as 
when the hand is rubbed against the sleeve 
of the coat ; but no heat has ever been ob- 
served from the friction of liquids. Tie heat 
evolved by friction seems to be owing to the 
same cause as that of percussion ; namely, a 



condensation of the substances rubbed. This 
condensation is, in some cases, permanent ; 
but when the bodies rubbed are soft, it can 
only be momentary. The heat evolved by 
friction is sometimes very considerable. 
Thus Count Rumford boiled water by the 
heat evolved by rubbing a steel borer against 
a cylinder of gun metal ;. and in our own day 
it has been proposed to heat factories where 
there is a superfluity of power, by running- 
large metal disks against each other. 

In a great number of cases, a change of 
temperature takes place when bodies com- 
bine chemically with each other. Sometimes 
the compound becomes colder than before, 
and sometimes hotter. When sulphate of soda 
in crystal, pounded, is dissolved in water, a 
considerable degree of cold is produced, and 
the cold is still more intense if the salt be 
dissolved in muriatic acid. If muriate of 
lime, in powder, and dry snow be mixed to- 
gether, so great a degree of cold is produced 
that mercury may be frozen, if it be sur- 
rounded by such a mixture. Potash and snow 
produce an equal degree of cold. When 
nitric acid or sulphuric acid is poured upon 
snow, the snow dissolves, and an intense cold 
is produced. On the other hand, when sul- 
phuric acid and water are mixed, so great a 
heat is evolved that the liquid is consider- 
ably hotter than boiling water. Heat also is 
produced when nitric acid and water, or 
water and alcohoLare mixed together ; and heat 
is also produced if sulphate of soda, in a state 
of efflorescence, is dissolved in water. An 
intense heat is produced by dissolving quick- 
lime in sulphuric acid. In most of these 
changes of temperature, water is either one 
of the substances combined, or it forms an 
essential constituent of one of them. The 
heat or cold produced depends often on this 
constituent. Thus, sulphate of soda, contain- 
ing its water of crystallization, produces cold 
when dissolved ; while the same salt, de- 
prived of its water of crystallization, produces 
heat. If the new compound be more fluid 
than the two constituents of it, the tempera- 
ture sinks ; if it be less fluid, the temperature 
rises. Thus, when snow and common salt 
are mixed, they gradually melt and assume 
the form of a liquid, and the temperature 
sinks to zero. Solid water cannot become 



54 



AMERICAN HOROLOGICAL JOURNAL 



liquid without combining with a quantity of 
heat, and the same rule applies to all solid 
bodies that become liquid ; hence, the cold 
evolved in these cases. The water of crystal- 
lization in sulphate of soda is solid ; it be- 
comes a liquid when salt is dissolved ; hence 
the cold produced. When the same salt, free 
from its water of crystallization, is thrown 
into water, it combines with a portion of the 
water, and renders it solid ; hence the heat 
evolved. When the density of two liquids 
united is greater than the mean, heat is 
evolved, because the specific caloric of the 
new compound is less than that of the con- 
stituents. This was first observed by Dr. 
Irvine, and it accounts for the heat evolved, 
when water is mixed with sulphuric, nitric 
acid, or alcohol. Thus it appears that the 
changes of temperature produced by mixture 
are either occasioned by the change of state 
which the water undergoes, or by a diminu- 
tion of specific caloric, in consequence of the 
new combination. 

The heat excited by the galvanic or electric 
shock has been commonly referred to a me- 
chanical cause, although upon this point a 
considerable diversity of opinion has prevail- 
ed. The effect, however, is well known to be 
very powerful, perhaps even more so than 
that produced b} T the convex lens ; but it is 
still more confined as to the extent of its 
operation. The agency of electricity in evolv- 
ing heat in bodies through which it passes is 
powerfully and wonderfully apparent in the 
discharge of the Voltaic battery. When an 
extensive series of plates, excited by an acid 
solution, discharges through points of char- 
coal, attached to stout wires connected with 
the opposite extremities of the battery, the 
heat evolved is most intense. With 2,000 
series of 4-inch plates Sir Humphrey Davy 
obtained an arched stream of light, of nearly 
4 inches in length ; fragments of diamonds 
on being introduced into it disappeared ; and 
thick wire of platina, one of the most refrac- 
tory of the metals, fused readily ; all the 
metals in their lamina?, such as gold and 
silver leaf, burned vividly. AVhen fine iron or 
steel wire was made to join the opposite ends 
of the battery, it immediately ignited ; and 
stout platina wire was kept at a white heat. 
The late Professor Daniel, by his new Voltaic 



battery, exceeded even these effects. With 
this battery the arc of electrical flame between 
points of charcoal was so intense, and in such 
volume, that the eyes of the spectators were 
seriously affected and inflamed, even though 
guarded by thick gray glasses, and the Pro- 
fessor's face became scorched by the heat as 
when exposed to a meridian sun. The rays, 
when collected into a focus, burned a hole 
readily through paper many feet distant ; 
and a bar of platinum, \ of an inch square, 
together with other highly infusible metals, 
such as rhodium, iridium, and titanium, were 
easily melted. We have ourselves melted 
iridium through the agency of the electric 
discharge, when every other means at our 
disposal failed. Whether in this operation 
the heat is, as it were, merely forced out of 
the wire by its commotion with its particles 
experienced from passage of the galvanic 
influence ; or whether, as has been supposed 
under certain circumstances, heat and elec- 
tricity can be converted into each other, or 
may be sej)ai ated by a kind of decomposition, 
are intricate questions of theory, upon which, 
at present, it neems beyond our power to- 
decide, and which must depend very much 
upon the opinion that we entertain respecting 
the nature of heat. The simple facts, how- 
ever, independent of hypothesis, seem to in- 
dicate that heat and electricity are distinct 
from each other whether they are to be re- 
garded as species of subtile fluids, or only the 
productions of matter. 

o 

The Difference. — Mr. Potance is a first- 
rate watchmaker. He keeps a neat little 
workshop just across the street from Gold- 
quartz, the rich jeweller. Potance says that 
sometimes (when his digestion is bad) t vexes 
him to see the elegant carriages drive up to 
Goldquartz's curb-stone, and the stylish occu- 
pants go in and leave their valuable watches 
with him for repair ; because, as soon as the 
carriage is gone, the watch will be sent to him 
to do — Goldquartz getting two-thirds of the 
pay, and all the credit. But he says (wi-h a 
sneer) there are ti:nes when those same ele- 
gant equipages do call at his door — to sell 
tickets for a church raffle, or to solicit him to 
subscribe to a fund to give his pastor (salary 
$5,000) a three months' recreation in Europe. 



AMERICAN HOROLOGICAL JOURNAL. 



55 



DIALING. 



NUMBER THREE. 



At the present day dialing is a more curious 
than useful art. Perfected astronomical in- 
s.ruments, and perfected watches and clocks, 
have very generally superseded it ; yet it is 
no loss to be in possession of any knowledge, 
and it may be useful to be acquainted with the 
method of drawing hour lines upon any sur- 
face or plane, for any place in the world, thus 
showing, by the shadow of a stile fixed on the 
plane, the approximate hour. The stile can 
have but three positions, viz., perpendicular, 
oblique, parallel. The dial planes upon which 
hour Lines may be drawn are — Horizontal , 
North or South, Erect-direct, Erect-declining, 
Pipelining-inclining, Reclining -declining, Con- 
vex, Concave. 

"We shall in this article give concise direc- 
tions for constructing dials upon many, and, 
perhaps, all of these planes, and shall begin 
with the Equinoctial Dial as being the 
ground and foundation of all other dials, and 
shows how naturally from it lines may be 
deduced for planes lying in other positions. 
The plane of this dial is parallel to the 
earth's equator, and is universal ; for lines 
drawn thereon will show the apparent time of 
day for any place in the world. 

To construct an equinoctial dial, procure a 
a metal plate about a foot (more or less) in 
diameter, or a thin board of good hard wood 
planed smooth on both sides, and secured 
from warping in the best possible manner. 




the hour figures ; divide the outer circle into 
24 exactly equal parts, making a point or dot 
at each division ; then draw lines from the 
centre to each of the 24 points, and these will 
be the true hour lines. For the stile, erect in 
the centre a pin or wire perpendicular to the 
dial plane. 

You will remember that 15° is equal to one 
hour in time ; therefore you could have con- 
structed this dial from a scale of chords, 
which you must construct thu«* : 




From a point in the centre draw three con- 
centric circles with your compass, to contain 



Draw a quadrant B 0, 90, and divide the arc 
into 90 equal parts, which number as 10, 20, 
30, etc. ; set one foot of your compass in B, and 
draw the arc 90, A. The line A B will be the 
chord of 90 to the radius C B. Carry all the 
degrees of the arc B to the straight line A B 
in the same manner, and number them 10, 
20, 30, etc., and you have a scale of chords. 
You can in the same manner make a scale for 
any size circle you may have occasion to use. 
In drawing this dial from the scale of chords, 
take the chord of 15° and lay it off to the 
right and left of the meridian line, and it 
would have given you the 1 o'clock and the 
11 o'clock hour lines. 15° more from these 
lines would have given you the 2 and 10 
o'clock ; and so on for the whole dial. But 
because the dial thus drawn will serve but 
for one half the year, when the sun is north 
of the equator (or equinox), from the 22d of 
March to the 21st of September ; therefore, 
to adapt it to the whole year, you must draw 
a corresponding dial on the other side, and 
the wire which forms the stile must extend 
through the board or plate 6 or 8 inches, and 
must be exactly at right angles to both sur- 
faces ; it only remains to set the dial truly, 
and it is completed. To do this properly you 



AMERICAN HOROLOGICAL JOURNAL. 



will need some instrument to measure alti- 
tude, and if you have none of the higher class 
of instruments for that purpose, you can 
make a Quadrant, which will answer your 
purpose well enough for dialing. Procure a 
piece of well-seasoned hard wood board of 
any size, from 6 inches to a foot in diameter, 
exactly square, and paste on one surface a 
sheet of drawing paper; then from one corner 
draw a quarter of a circle, as large as the 
board will admit of, the limb (or are) divided 
into 90 equal parts or degrees. To one of 
the straight edges you may, if you choose, fix 
sight vanes; then attach a thread at the point 
from which you described the segment, sup- 
porting a lead bob or plumb. Complete the 
instrument as represented by Fig. 9. 




By applying the edge of your quadrant to the 
stile, and raising it till the thread of your 
quadrant cuts the degree of latitude of your 
place, then the top of the stile is parallel to 
the earth's axis, and the plane of your dial is 
parallel to the plane of the equinoctial circle 
in the heavens. Still you need the 12 o'clock 
or meridian line, which may be found most 
readily by the method described in the articles 
on Astronomy in Vol. I. of this Journal. Lest 
some of our readers rnaj' not have seen those 
papers, and to make our instructions complete 
in themselves, we will repeat the directions. 

TO CONSTRUCT A MERIDIAN LINE. 

Prepare a horizontal plane of any size you 
wish, on the sill of a south window, or set up 
a post in the yard or garden, on which your 
dial is to stand; make the top of it truly level 
in every direction, which you can do with 
your quadrant ; on this plane draw several 



concentric circles as large as the plane will 
admit of ; in the centre set a wire stile exactly 
upright (a large knitting-needle is as good a 
thing as you can get). Before noon on any 
day when the sun shines, observe when the 
end of the shadow cast by the wire touches 
one of the circles you have drawn, and there 
make a dot ; after noon you must watch when 
the end of the shadow touches the same circle, 
and at that point make another dot ; draw a 
line between the two dots, and exactly sub- 
divide it ; a line drawn through that point and 
the centre of the circle will be a true meridian 
line. You may get the 12 o'clock line more 
exact by making a series of observations on 
the several concentric circles and taking the 
average of the whole. Then set the dial you 
have constructed, with its 12 o'clock line to 
correspond exactly with the meridian line you 
have just found, and fasten the dial in place 
by two or more strips of iron secured to the 
post and to the edge of the dial. 

Horizontal Dial is one whose plane lies 
parallel to the horizon, and is the most com- 
mon and most useful — the sun remaining on 
it from sunrise till sunset. The form of the 
plane on which you draw a dial is of no con- 
sequence — whether square, round, or irregu- 
lar — so the surface be a true plane ; neither 
is the size material, only the larger you con- 
struct it the more correctly can it be drawn. 
Fig. 10 represents such a dial, and its mode 
of construction. 




Draw three concentric circles as a margin 
to contain the figures ; draw the line A C, 
which is the substilar or 12 o'clock line (but 
not the meridian line on all dials), in which 



AMERICAN HOROLOGICAL JOURNAL. 



57 



line make choice of a point as at 0, a little 
above the centre (by which means you enlarge 
the hour spaces), through which point draw 
the line VI C VI, at right angles to A C, 
for the six o'clock hour line ; in the substilar 
line, as at E, make choice of another point, 
and through that, at right angles to A C, draw 
the line D F. Having proceeded thus far, let 
it be required to construct a dial for a given 
latitude, say 51° 47' N ; open your compasses 
to the chord of 60° ; set one foot in C, and 
draw the arc All; then take the chord of 
51° 47' and set it from A to B, and draw the 
line C B, which gives you the true form of the 
stile, or dial cock, as it is sometimes called ; 
set one foot of your compasses in E, where 
the line DEF cuts the meridian line, and 
take the nearest distance to the hue C B, or 
stile's height ; turn that point of your com- 
pass about and make another mark on the 
12 o'clock line at H, which represents the 
centre of the equinoctial ; on H, as a centre, 
draw the quadrant Gr E, and divide it into six 
equal parts ; lay a rule to H, and those sev- 
eral equal points, and where the ruler cuts 
the line DEF, are the points through 
which the hour lines must pass ; then lay the 
ride to the centre C, and to those points in 
the line DEF, and draw the hour lines ; 
set off the same distances in the line DEF, 
from E toward F, and draw the morning 
hours ; those before six in the morning and 
after six p. >i. are drawn by continuing the 
same hour lines beyond the centre at C The 
dial, after being correctly drawn, must be 
truly set, or it will give erroneous indications 
of time ; therefore the utmost care must be 
exercised in setting it so that the 12 o'clock 
hour line will coincide with the meridian you 
have drawn on the place selected for your 
dial. 

An Erect South Dial is nothing more than 
an upright south wall (which is the dial 
plane) and faces the exact south point of the 
horizon. As in the horizontal dial the eleva- 
tion of the pole was equal to the latitude of 
the place, so in this it is the complement of 
the latitude. The sun never shines twelve 
hours on this dial, except when it is in the 
equinoctial, because the plane itself lies in the 
prime vertical, and from March 20th to Sep- 
tember 23d the sun does not come due east 



until after six a. m., and is due west before 
six p. m. In constructing this dial draw the 
line VI VI across the plane you have made 




choice of for the east and west line, or the hour 
line of six o'clock; from A let fall the perpen- 
dicular A F, for the 12 o'clock line; then with 
your compasses take 60° from the scale of 
chords and draw the arc B C VI; then take 
the complement of the latitude of your place 
from the same scale, and lay it from B to C, 
and draw A C, which is the height of the 
stile; make choice of any place in the 12 o'clock 
line, as at I, and draw the line DIE, 
parallel to VI VI; set one point of your com- 
pass in I, and take the nearest distance to the 
line A C; turn your compass down to F, and 
from that point describe the semicircle G I 
H, and divide it into 12 equal parts, for the 
semicircle represents one-half of the equinoc- 
tial; lay a rule to those points and to the 
centre F, and mark the points where it cuts 
the line DIE; then draw lines from A 
through those points, and they will be the 
true hour lines. If you wish the ^ hour divi- 
sions you must divide the semicircle into 48 
equal parts and draw the lines the same as 
for the hours. Of course at the end of the 
hour lines on the left you place the morning 
hours, and the afternoon hours on the right. 
If your dial be large you had best use an 
iron rod, about the thickness of the lines you 
draw for hour lines, being careful to fasten it 
exactly over the 12 o'clock line. The angle 
it makes with the plane of the dial (comple- 
ment of the latitude) you can fix by your 
quadrant. "When the thickness of the stile is 
appreciable, you must make allowance for it 



53 



AMERICAN HOROLOGICAL JOURNAL. 



in drawing the two quadrants which you di- 
vide for the hour distances, and you must 
take a centre for each at F, just the half dia- 
meter of your iron rod or stile distant from 
the 12 o'clock line, otherwise your dial will 
go too slow in the forenoon and too fast in 
the afternoon. 



ADJUSTMENT TO TEMPERATURE AND POSITION. 



This subject, although one well worth the 
earnest consideration of every watchmaker 
making any pretence to a thorough knowl- 
edge of his business, is, nevertheless, but very 
little understood or practised by repairers in 
the country. The reason for this may be 
traced to two causes. First : The scarcity of 
workmen qualified to impart to others this 
very necessary branch of Horology ; and 
Second : That those who are qualified, mainly 
for mercenary motives, keep it a secret — 
something not to be divulged. This state of 
affairs is not alone confined to this branch, 
but to very nearly all branches of Horology ; 
and thus it is, on looking around us, that we 
see so many poor workmen. Desirous of 
bringing about a better state of affairs, I 
shall, in the following article, give my method 
of accomplishing Adjustments to Temperature 
and Position. 

As it is not possible to keep a watch in one 
and the same position at all times, it is there- 
fore very essential to the good performance 
of the watch to adjust it so that the friction 
in one position shall coincide with that in 
another ; so that the watch in one position 
loses or gains as much time as in another. 
To accomplish this I strictly observe the fol- 
lowing rules : 

First. — The balance-staff pivots must have 
the least possible diameter in proportion to 
the size and weight of the balance. 

Second. — The pivots must be well hardened, 
te npered, and polished, so as to cause as 
little friction as possible. 

Third. — The jewel holes must somewhat 
have the form of an hour-glass, whereby the 
friction is considerably lessened; that is, more 
so than if they were cylindrical. 

Fourth. — Tha ends of the pivots must be 



made nearly flat, whereby the regulation of 
this adjustment is brought under perfect 
control. 

Fifth. — The hair-spring must be so placed 
that the coils are perfectly concentric to the 
balance-staff ; and after winding the watch, 
set the hands to the exact time, as indicated 
by a good regulator, and allow it to run six 
hours in a vertical position. After this lapse 
of time the difference between the watch and 
regulator is carefully noted, and the watch is 
again wound and set, and again run six hours 
in a horizontal position, and the difference of 
time likewise noted. On comparison of these 
two results, should the watch have lost or 
gained as much time in one as in the other 
position, then the desired result is already 
accomplished ; but should the watch, for in- 
stance, have lost more time in a vertical than 
in a horizontal position, this will denote that 
there is too little friction in a horizontal, 
compared to that in a vertical position ; and 
consequently the ends of the pivots must be 
still more flattened, whereby the friction in a 
horizontal position is increased, and the 
watch will lose time in proportion to the 
amount of face given to the ends of the pivots. 
But should the watch, on the contrary, have 
gained time in the vertical position, this will 
denote that the friction in a horizontal position 
is too great, compared to that in a vertical 
position ; and in this case, by rounding the 
ends of the pivots in proportion to the time 
lost in a horizontal, compared to that in a 
vertical position, the balance will move 
more free, and the watch will gain time in 
that position. These alterations of the ends 
of the pivots must be continued until the 
watch in every position runs alike. If the 
watch should by these experiments and 
alterations have been caused to gain or lose 
time, it can afterwards be regulated by the 
hair-spring. Although the watch may be 
provided with an isochronous spring, it is, 
nevertheless, of the greatest importance to 
carefully adjust it to position, even if there is 
only the slightest difference of time discern- 
ible between the different positions. 

After the watch is so far completed that it 
will in every position run alike, and after it 
has been provided with an isochronous 
spring, it is then the proper time to adjust to 



AMERICAN HOROLOGrlCAL JOURNAL. 



9 



temperature (heat and cold). The first con- 
sideration is, that the watch be well-regulated. 
It is often the case that it gains or loses very 
slightly, and the regulator (if it has any) is 
too sensitive to regulate with ; in that case 
it will be found necessary to resort to the 
screws on the balance for the desired results 
to be attained. The manner in which this is 
effected is thus : If the watch gain time, one 
or more screws on each arm of the balance 
must be unscrewed, in proportion to the 
amount of time gained ; if, on the contrary, 
the watch loses, the screw or screws must be 
turned in further, in proportion to the time 
lost. It must be strictly observed that the 
balance, in all these alterations of the screws, 
remain exactly poised ; when the above direc- 
tions have been followed and completed, we 
proceed to adjust to temperature. First, 
construct a box of tin or copper, with about 
four or five compartments, one above another; 
the upper one large enough to hold a ther- 
mometer; these compartments must allbe her- 
metically closed ; beneath this apparatus 
place an ordinary alcohol lamp, and allow it 
to remain lighted until the upper section 
shows a heat of 130 Q to 135° Fahr., which is 
the limit to which the watch should be sub- 
jected, and should be kept up to the same 
number of degrees, by alternately placing 
and removing the lamp from beneath the 
apparatus. The watch is then placed in the 
upper section, and allowed to run six hours in 
that temperature (first having wound and cor- 
rectly set it) ; it is then taken out, and the 
difference of time noted ; the watch is then 
placed in a refrigerator where the tempera- 
ture is 10° to 15° below zero, being wound 
and set, and allowed to run six hours ; the 
difference is here likewise noted, and then 
compared with the first. Should the watch 
in both temperatures run the same, the 
desired result is then already attained ; but 
should the watch while in the heated box 
have lost time, it will denote that the com- 
pensation is not strong enough, and conse- 
quently requires strengthening, which is ac- 
complished by moving one or more screws 
''according to the time lost) towards the cut 
part on each arm of the balance, whereby the 
weight of the screws becoming more active, 
causes the compensation to be strengthened. 



But if, on the contrary, the watch, while in 
the heated box, shows to have gained time, it 
denotes that the compensation is too strong, 
and to weaken it will require the screw or 
screws on each arm of the balance to be moved 
further back from the cut part, in proportion 
to the time gained. This moving must be 
continued until the watch, in high and low 
temperatures, keeps time alike. It sometimes 
happens that the screws are not of sufficient 
weight to influence the compensation, 
although they be moved to the very verge of 
the cut part ; in that case, heavier screws 
must be substituted. It also sometimes hap- 
pens that the compensation of itself is so 
strong as to require lighter screws to be sub- 
stituted. It must, however, be borne in 
mind, that by all these changes of position, and 
weight of the screws, the balance must not be 
brought out of poise, and a screw on one arm 
of the balance must not be moved an iota fur- 
ther than the screw exactly opposite (in a 
line through the centre of the balance with 
itself). Care must also be taken that the 
weight of the balance remain the same. It is 
strongly advised that the slightest error in 
the going of the watch in either temperature 
should not be tolerated, for the regularity in 
its time-keeping hereafter depends much on 
the manner in which the watch has been pro- 
vided with this adjustment. 

Having occasion, since my last communi- 
cation, to adjust a chronometer to isochron- 
ism, I resolved to test Mr. Sandoz's theory. 
After one failure; I succeeded in establishing 
a correct isochronism. I then repeated the 
experiment on another watch, and the result 
was good ; and I think his method of causing 
the vibrations of the balance to become isoch- 
ronous is one that may be safely adopted. 

Chas. Spiro. 



JEWELLING. 



The articles that appeared in the Journal 
some time ago upon Jewelling, although very 
interesting, were not "exhaustive," so I have 
concluded to give my ideas upon that subject. 
That I am qualified to have " my say," I will 
premise my remarks by stating that I at one 
time had charge of the jewelling department 
in the factory that produces that unexcelled 



60 



AMERICAN HOROLOGICAL JOURNAL. 



American watch, known as the "Howard 
watch," manufactured by E. Howard & Co., 
Boston, Mass., since which time I have, as 
the Drs. say, enjoyed quite an extensive 
" private practice." 

I shall not stop to detail the evil effects of 
the method employed by those who have no 
foot lathe in putting in jewels, as they are 
too well known to the better class of work- 
men, but proceed to detail my method, ap- 
pliances, results, etc., as far as they relate to 
the ordinary replacing of a broken jewel. If 
the reader wishes to jewel a watch that has 
never been jewelled, I refer him to the articles 
upon that subject that appeared in the Hoko- 
logical Journal some time ago. 

As it will not pay for a watchmaker to 
make his own jewels, he ought to have a good 
stock of fine jewels; and I am free to confess 
that I have never yet seen a really fine article 
offered for sale by the material dealers in this 
country. I send to London, England, for 
mine, and get a very superior article. A 
good foot lathe is of course indispensable ; 
with which, and his jewels and some diamond 
powder, he is prepared to do a neat and 
clean job. 

On page 13, Vol. I., No. 1, is detailed the 
manner of preparing the diamond powder 
for use ; only substitute sperm oil for sweet 
oil, as the latter will get thick and gummy 
after it has been exposed to the air for some 
time, and for a watchmaker three old style 
oil cups, such as hold over a teaspoonful, 
will answer the purpose of saucers, and are 
much more convenient. As so little oil can 
be used, the first receptacle should only stand 
some ten or fifteen minutes before decanting 
off ; the second about two or three hours. 
After all the diamond powder is settled to the 
bottom of No. 3, the surplus oil can be 
poured off. Before the powder is prepared 
it would be best to have a velvet-lined box, 
made by a manufacturer of jewelry boxes, to 
hold the three glass cups, as they can always 
be kept together and free from dust ; \ 
of a carat will be a sufficient quantity to pre- 
pare at once. As the modus operandi for jewel- 
ling a new or plain watch is given in the arti- 
cles on Jewelling, I shall, as before stated, 
confine myself to that class of work that usu- 
ally falls into the hands of the watch repairer. I 



One frequent cause of a watch performing 
badly can readily be traced to its imperfect 
jewels. A watchmaker should always care- 
fully examine every jewel in a watch that he 
has down for repairs, and if he finds one the 
hole of which is too large, or very much " out 
of round " — that is, much wider in one direc- 
tion than another — it should be replaced by 
a good one, as follows : If the depth is 
correct, notice whether the jewel is above 
or below the surface of the plate ; if it is 
either, then knock it out, and cement the 
plate or bridge on a chuck in the lathe, being 
careful to get it on true by the hole lately oc- 
cupied by the jewel; by means of a burnisher, 
such as is described on page 106, Vol. I., No. 
4, raise the burr that holds the other jewel in, 
and if a jewel can be found of the proper size 
and thickness, and the hole not too large, it 
can readily be " rubbed in " with the bur- 
nisher ; if the hole is too small, it can be 
opened, as described on page 75, Vol. I., No. 
3. I make these refei'ences for two reasons : 
first, to avoid repeating what has already 
been written, and, secondly, to call particu- 
lar attention to those passages in the articles 
on Jewelling, that should be fully understood 
before the novice attempts to set or open a 
jewel. The chuck on which the article is ce- 
mented should have a hole from a quarter to 
half an inch deep in its centre. If no 
jewel can be found of the right size and 
thickness, select one a little too large, enlarge 
the hole sufficiently to fit the jewel, then pro- 
ceed to fasten it in, as described on page 106, 
Vol. I., No. 4. If the jewel is broken, of 
course the same remarks apply to replacing 
it with a good one, as to an imperfect one. If 
the jewels are contained in settings screwed 
in, simply take out the setting and proceed 
with it the same as with a plate or bridge. 

One difficulty that the watchmaker has to 
contend with in selecting a jewel from such 
as are sold in this country, is to find one the 
hole of which is in the centre of the jewel, as 
all the refuse and trash in the way of jewels 
are sent from Europe to this country for sale. 
Those who wish to obtain a very superior arti- 
cle, every one of which will be perfect, can do 
so by sending to Samuel Holdsworth, 54 
Spencer street, Clerkenwell, E. O, England. 
I simply mention this gentleman's name, as I 



AMERICAN HOROLOGICAL JOURNAL. 



61 



have obtained some jewels from bim ; no 
doubt but what otber parties tbere furnisb 
equally good jewels. If a jewel is not true, 
or ratber, if tbe bole in it is not in tbe cen- 
tre, it must be cemented into a chuck in tbe 
latbe, trued up by tbe bole, then turned off 
witb a diamond cutter, and tbe cbamfer 
carefully trued up and polisbed again ; wbile 
on tbe latbe it can be turned down to fit tbe 
bole in tbe setting or plate ; tbe sbellac is to 
be removed from tbe plate witb alcobol. In 
many instances a cbuck will bave to be 
turned up to suit tbe particular job to be 
done. Care must be taken in opening, or tbe 
jewel will break or cbip around tbe bole. 
Tbe corners must be carefully rounded by a 
piece of wire larger tban tbe bole, tbe end of 
wbicb is conical. It will take but a moment 
to do tbis, but if care is not taken, too mucb 
will be taken off. 

Now any one wbo bas carefully read tbe 
articles upon Jewelhng, and are supplied witb 
tbe tools and materials above mentioned, 
will, by exercising a due amount of care and 
patience, be enabled to do a job tbat be will 
not be asbamed of. 

Jas. Feickee. 

AiCEEicrs, Ga., August 8th, 1870. 



OHX BLISS & CO.'S DIPliOYED TRANSIT 
INSTRUMENT. 



Tbe science of Horology, in its mere me- 
chanical branch, or tbe art of constructing 
tbe most intricate and perfect machines for 
the purpose of measuring time, would be in- 
complete without a true and reliable standard 
to test it by. Moved by an appreciation of 
this necessity, skilful workmen have at dif- 
ferent times exerted their ingenuity to invent 
the means for obtaining such a standard, and 
their labor has been variously crowEed with 
success ; but without a question the standard 
time obtained by means of transit observa- 
tions of heavenly bodies is the most reliable. 

Hitherto the instruments for such observa- 
tions have been confined to artronomical 
observatories and colleges, because of the 
great expense involved in connection with 
them, and scientific men only have been sup- 
1 capable of mastering them, as it re- 



quired a degree of education not commonly 
found among others ; but this need no more 
be the case. Horology is only a part of the 
great science of astronomy, and the transit 
instrument really belongs to the trade. 

In the beautiful production of a transit 
instrument by the above firm, the trade is 
furnished with the means of obtaining a cor- 
rect standard of time, and at a very small 
cost compared witb the benefit to be derived 
from it ; moreover, these gentlemen have 
furnished a method of setting in the meridian 
and computing transits, so that the most in- 
experienced cannot fail to accomplish it in 
the first trials, and their instructions are so 
simple that any one being able to read can 
understand them. 

The result of their invention is a decided 
step in advance in the progress of Horology, 
inasmuch as it brings it within the reach of 
the poorest storekeeper to possess one of 
their instruments. Though quite small, it is 
nevertheless susceptible of the most delicate 
adjustment, in every respect equal to those 
in large observatories. An inspection of the 
results of its operation will establish the truth 
of this beyond a doubt. The following results, 
which are copied from the daily account of our 
observations of the sun, though not absolutely 
perfect in uniformity as to tbe fractions, will, 
nevertheless, testify to the accuracy of the 
instrument : 







SECS. 








SECS. 


July 28. 


Clock fast 


= 8.82 










" 29 


u 


9.63 .. 


.. G 


ain 


per day . 


... 0.81 


" 30 


11 


10.41 . . 




it 


" 


. . . 0.78 


Aug. 1 


If 


11.66 .. 


. 


It 


" 


... 0.62 


" 2 


II 


12.19 .. 




II 


" 


... 0.53 


" 3 


II 


12.80 . . 




" 


" 


... 0.61 


" 4 


•' 


13.47 . . 




II 


ii 


... 0.67 


" 5 


it 


13.6 .. 




II 




... 0.20 


" 6 


" 


14 09 .. 








. . . 0.42 


" 8 


If 


15.12 .. 






" 


... 0.51 


" 9 


(I 


15.78 . . 




II 


ii 


.. 0.66 



The clock was set to correct time on the 
15th of July, which for the twenty-five days 
to the 9th of Aug. makes its average gain per 
day 0.63 of a second; the greatest deviation 
from which in the last ten observations is only 
0.4 of a second. 

In connection with our solar observations, 
and for the purpose of proving these correct, 
we also observed transits of fixed stars of dif- 
ferent altitudes. On tbe 5th of Aug. we 



62 



AMERICAN HOROLOGICAL JOURNAL. 



observed the transit of y Draconis Decl. 51° 
30' North; at 8h. 57m.49s.53 its true meridian 
passage was at 8h. 55m. 59s. 22, making clock 
fast lm. 50s. 31. For the convenience of travel 
the clock is set to Philadelphia time, which 
is lm. 36s. 43 faster than our time. Subtract- 
ing this, makes clock fast 13s.88. 

The same day we observed the transit of 
H' Sagittarii Decl. 21° 5' south, making clock 
fast 13s. 63 ; also that of Vega Decl. 38° 39' 
north, made clock fast 13s. 78. 

Frequent comparison of our time with that 
of Wm. H. Harpur, of Philadelphia, also made 
it, as near as we can tell, correct to the second. 

It is doubtful that a much nearer approach 
to perfection could be made with a transit of 
larger dimensions ; but certain it is, that for 
all practical purposes this is near enough, 
and we can recommend it with the utmost 
confidence to all who take pleasure in their 
business. It is not only a comfort and satis- 
faction to be able to determine the correct 
time, but the money which the instrument 
costs is invested at large interest. 

Theo. Gribi. 

Wilmington, Del. 



PINION MEASUREMENT. 



There probably is no part of watch-making, 
excepting the escapement, that is susceptible 
of more careful adjustment, than the depthing 
of the wheels and pinions ; for the regularity 
in the going of the watch depends as much 
on these depthings, as it does on the careful 
adjustment of the parts comprising the 
escapement, and it matters little how well 
shaped, or how well finished the teeth of 
either wheel or pinion may be, if the depth is 
not correct the result will be very unsatis- 
factory. Then, again, if the size of the pinion 
is out of proportion to the size of the wheel, 
the workman will assuredly find it an im- 
possibility to obtain a correct depth. For 
that reason I have prepared the following 
table of pinion measurements, which, if 
exactly followed, will enable any workman 
to determine the exact size of pinion required. 
I have purposely withheld a description of 
the mode of calculation by which these tables 
have been obtained, for the reason that the 



majority of repairers have not the education 
required to fully understand it, and it would, 
therefore, seem dry and uninteresting. It 
must be understood that the measurement 
of the diameter of a pinion, in this table, is 
constantly on the wheel by which it is driven. 
A pinion of 6 leaves must have the diameter 
of 3 teeth, measured on the wheel, from the 
very top of the first tooth to the top of the 
third tooth ; for clocks, it must have 3 full 
teeth, — that is, from the outer side of the first 
tooth to the outer side of the third tooth. A 
pinion of 7 leaves must have the diameter of 
3 full teeth ; for clocks, 3£ full teeth. A 
pinion of 8 leaves must have the diameter of 
3| teeth, measured from the tops of the teeth ; 
for clocks, 4 teeth, also measured on the 
tops. A pinion of 9 leaves must have the 
diameter of 4i teeth measured on the tops of 
the teeth ; for clocks, the same. A pinion of 
10 leaves must have the diameter of 4 full 
teeth ; for clocks, the same. A pinion of 11 
leaves must have the diameter of 4^ full 
teeth ; for clocks, the same. A pinion of 12 
leaves must have the diameter of 4| full 
teeth ; for clocks, 5 full teeth. A pinion of 
13 leaves must have the diameter of 4| full 
teeth ; for clocks, the same. A pinion of 14 
leaves must have the diameter of 6 leaves, 
measured on the tops of the teeth ; for 
clocks, the same. A pinion of 15 leaves must 
have the diameter of 6 full teeth ; for clocks, 
6£ full teeth. A pinion of 16 leaves must 
have the diameter of 6| full teeth ; for clocks, 
6 \ full teeth. There is an instrument sold in 
the tool shops named the Proportion Circle, 
which has for its object the measurement of 
the diameter of the pinion by the size of the 
wheel, and vice, versa ; but this tool is only of 
use when new, for they are very apt to get 
bent, and otherwise out of order, which con- 
dition renders it useless, — for where there is 
such precision required, as in the measure- 
ment of a pinion, this cannot be tolerated. 
But if the workman will take the trouble of 
committing to memory the few directions 
given above, it will repay him by having not 
only an instrument always at hand, but one 
that will never get out of order, and always 
be correct. 

Charles Spiro. 
918 Eighth Avenue, N. Y. 



AMERICAN HOEOLOGICAL JOURNAL. 



63 



OETHO-CHEOXOGRAPHY. 



In the June number of the London Horo- 
logical Journal is the description of a very 
useful, simple, and portable instrument for 
getting- the apparent time at meridian. 

"We shall take pleasure in some future 
number in giving a full description and mode 
of using it. We were a little surprised at 
the name the inventor chose for it. Had it 
been an American invention, it -would not 
have been strange ; but in England, where 
" Chronography " was well known as a species 
of literary art, and as samples of it are scat- 
tered all over the kingdom — on churches, 
monuments, dials, books, etc. — it seems hardly 
correct to apply the name to the instrument 
described. The inventor calls it an Ortho- 
Chronograph. As we understand the word 
here, its literal meaning would be writing the 
correct time. Had he called it an Ortho- 
Chronoscope it would have been correctly 
named, for it really is a view of the coiTect time. 
It may be of interest to some of our readers 
to know a little about the quaint art of 
" Chronography." Here, in the New World, 
those old fashions, relics of the past, are not 
constantly before us as they are in Europe, 
and consequently seldom thought of. The 
practice of making chronographs for the ex- 
pression of dates in books and epitaphs (and 
especially on medals and coins) was a very 
common literary amusement as early as the 
sixteenth and seventeenth centuries. One of 
the most remarkable, commemorating the 
death of Queen Elizabeth, is as follows : " My 
Day Is Closed In Immortality." The arith- 
metical formula of which is M = 1000 -j- D 
=500 -f C = 100 -f III =3 ; the whole sum 
= 1603. 

In the second paper by Addison, on the 
different species of false wit {Spectator, No. 
60), is noticed the medal which was struck 
off to Gustavus Adolphus, with the motto 
"Christ Vs Dec X ergo tr IVMphVs" If 
you take the pains, continues the author, to 
pick the figures out of the several words, and 
arrange them in their proper order, you will 
find they amount to MDCXVWH., or 1627 
— the year in which the medal was stamped. 

The following is the quaint title of a book 
printed in 1661 : " Magna Charta ; Or the 



Christian's Character Epitomized. In a ser- 
mon preached at the funeral of the Right 
Worshipful, the Lady Mary Farewell, at Hill- 
Bishops, near Taunton, by Geo. Newton, 
Minister of the Gospel there. 

D. FareweLL ob It Maria saLVt Is 

In anno 
Hosannos posltos VIXIt and Ipsa 
VaLe." 
The four Latin lines with which the title con- 
cludes form a chronogram, or inscription, 
comprising a certain date and number, ex- 
pressed by those letters inserted in large 
characters, which are to be taken separately 
and added together according to their value 
as Roman numerals. When the arithmetical 
letters occurring in the first two lines are 
thus taken, they will be found to compose the 
year 1660, when the Lady Farewell died (as 
the words declare) ; and when the numerals 
are selected from the last two lines they ex- 
hibit 74, her age at the time, as they also 
indicate, thus — 

D= 500 1= 1 

LL= 100 VIXI=17 

1= 1 

MI 1001 VL = 55 

LVI 56 — 

II 74 



1660 



The lady who was commemorated in the 
inscription was the daughter of Sir Edwd. 
Seymour, of Berrie Castle, in Devonshire, and 
was the wife of Sir Geo. Farewell, Knight. 
It was recorded in the epitaph on his monu- 
ment at Hill-Bishops, that she died Dec. 13, 
1660, and that she was the mother of twenty 
children. 

The above chronograph singularly illus- 
trates a passage in Shakespeare. It will be 
observed that the Rev. G. Newton takes 
advantage of the double letters at the end of 
Farewell to express 100. See how the " good 
M. Holofernes," in Love's Labor Lost, intro- 
duces the same thought into his sonnet, as an 
exquisite and far-fetched fancy — 

" If Love be sore, then L, to sore, 
Makes Fifty Sores ; Oh ! sore L ! 
Of one sore I an Hundred make 
By adding but one more L." 



64 



AMERICAN HOROLOGICAL JOURNAL. 



On the upper border of a sun-dial, affixed 
to the west end of Nantevich Church, Che- 
shire, there appeared, pievious to its removal 
about the year 1800, the following inscription: 
"Honor Do MIno propa Ce VLo sVo parta." 

The numerals, it will be seen, make up the 
number 1661, which was the year of the 
coronation of King Charles II., and no doubt 
the year in which the dial was erected. 

The banks of the Rhine furnish abundant 
examples of this literary pleasantry, on the 
beams of churches — on the fronts of galleries 
— over church doors — some in stone, some in 
wood — many with the capitals rubricated. 

When our own wonderful antiquities are 
investigated, and the buildings and structures 
and carvings of the great South-west come to 
be studied, and their hidden meaning (if 
there be any) is known, possibly the New 
World may prove to be the oldest. 



NEW STAKING TOOL. 

Mr. D. M. Bissell, of Shelburne Falls, 
Mass., has just obtained a patent on his 
staking tool, and will immediately take steps 
to introduce it to the trade. 

The nature of this invention consists in the 
use of a solid block of iron or other metal, in 
which is closely fitted a cast steel plate span- 
ning a deep groove in the block. In this plate 
are a series of holes, graduated in size, so as 
to allow the pivot of a wheel or pinion to pass 
through, and the wheel to rest upon the flat 
surface of the plate while being operated 
upon. A movable guide is so arranged, that 
a punch or other tool desired to be used may 
be brought directly over any one of the holes 
in the plate, and secured by a set screw. 
This device is very useful for riveting wheels, 
as well as for rounding and stretching ; also, 
as a freeing tool, and for finishing bushings, 
closing rivet holes, removing table rollers 
from balance staffs, and various other pur- 
poses. 

Want of space prevents our giving any 
detailed description at this time ; but its 
many advantages will be seen from the fact 
that the small tools used (and to which there 
is scarcely any limit) all have a perfect guide, 
so that the working must necessarily be ac- 
curate. 



JEAN PAUL GAENIEK. 



Jean Paul Grarnier was born at Epinal 
(Vosges), in November, 1801. His father 
dying when he was ten years old, left him to 
provide for himself. Commencing in a print- 
ing house, he soon left for a locksmith's shop, 
and from there to a clockmaker, where he re- 
mained contented. When a skilful workman, 
the great reputation of a master Horologist 
in Luseuil attracted him there, where he re- 
mained till 1820, when he went to Paris to 
join Lepine, who was then at the height of 
his renown. After five years spent with him, 
G-arnier established himself in business alone. 
Soon after he invented and presented to the 
Academy of Sciences a free Remontoir escape- 
ment of constant force, marking the seconds 
with a pendulum of half-seconds vibration. 
This escapement was founded on a new prin- 
ciple, as its pendulum was removed from the 
variable action of its motive power, and was 
highly approved by MM. Arago, Molard, and 
Mathieu. 

He presented to the Exposition of 1827 a 
regulator, with astronomical arrangements, 
which he constructed entirely without the aid 
of machinery. It was distinguished by the 
beauty and finish of all its parts, the simpli- 
city of its mechanism, and the exactitude 
with which it indicated the most complicated 
astronomical facts. It also represented the 
annual revolution of the sun ; its entrance into 
the zodiacal signs ; the equation of time ; the 
rising and setting of the sun ; as well as the 
periodical, synodical, and daily revolution of 
the moon, and its various phases, having but 
a few seconds of error during the entire 
year — the effect which different temperature 
produced on the ball of the pendulum being 
compensated by two movable bodies which 
act in an inverse sense and maintain the same 
arcs of vibration. 

His profound knowledge of the most dif- 
ficult questions of Horology placed him in 
communication with the most celebrated and 
accomplished artists of Europe, among others 
with Antide Janvier, who was proud to com- 
plete the instruction of a young man of such 
rare talents. 

Garnier's next invention was a Sphygmom- 
eter, an instrument which indicates to the 



AMERICAN HOEOLOGICAL JOUKNAL. 



65 



eve the movements of the pulse, and which, 
till then, had only been known by the touch. 
This has become indispensable in the study 
of the circulation of the blood, and has merit- 
ed the highest encomiums of Drs. Marey and 
Magendie. 

The invention of a new escapement, ap- 
plicable to portable clocks, by its simple 
arrangement and easy manufacture, gave rise 
to a new kind of timepiece, called Pendicle de 
Venture, which met with such success that 
several millions per annum are manufactured 
in France. Some years later he improved 
these, making them give, on the same dial, 
the days of the week, month, and the phases 
of the moon. 

He next applied to ship chronometers the 
free Kemontoir escapement of constant force, 
causing the balance to describe arcs rigor- 
ously correct, dispensing with the fusee here- 
tofore used in all chronometers. About the 
same time he invented a new Metallic Ther- 
mometer ; also a Micrometer so delicate it 
indicated a variation of ^Voo" millimetre. 

Not content with his already great reputa- 
tion, he continued hi3 inventions, next 
making the reckoner, or meter, which, when 
attached to any machinery, gives its revolu- 
tions and movements, arranging the figures 
on a single line, that they may be read in a 
moment. So necessary has this become to 
all machines, that there are now many houses 
devoted entirely to its manufacture. After- 
wards he made it yet more complete by 
adding an attachment giving the hours, min- 
utes, and seconds. Either could be used 
separately; and together, it registered, at 
once, the number of revolutions of the ma- 
chinery, and the length of time of its work- 
ing. This was adopted by the Marine and 
Financial Departments, and applied to steam- 
boats and the Mediterranean mail-packets. It 
is useless to enumerate single instances, so we 
will content ourselves with this extract from the 
report of one of our first engineers : " The Gar- 
nier Computing Meter, for locomotives, gives 
the number of revolutions of the wheels, conse- 
quently the distance passed over by their cir- 
cumference, also the difference between this 
and the space actually gone over, from which 
we find the slipping. It gives the attendance 
and feeding of the engine at the stations. 



With the clock attachment it gives the num- 
ber of revolutions during the time the engine 
has worked. On the arrival of a train, whose 
time of leaving is noted on the conductor's 
schedule, this meter gives, by the clock, the 
time the engine has worked ; by the meter, 
the space traversed by the wheels. The dif- 
ference between the total time of the trip, and 
the total stoppings at intermediate stations, 
gives the mean speed of the train. It shows 
the comparison of the fuel used with the dis- 
tance passed over. 

" For steamboats it indicates the number 
of revolutions and the space gone over by the 
paddle-wheels, or screw, in a given time, as 
well as the time of working the engine. The 
variations of effect on the engine by currents 
of different depths of water are also indicated 
by it. The detention at stations, and the ac- 
celeration by the sails, are given. It gives 
the motive power — as compared with the 
speed of the boat — the number of revolutions 
made by a given amount of steam — the ex- 
pense per hour of the fuel consumed — and, if 
furnished with an indicator, the quantity of 
water vaporized deducted from the specific 
weight of the steam at the pressure given in 
the cylinder. This meter, connected with 
the piston, indicates the volume of water 
flowing into the boiler in a given time, and 
compares it with the steam furnished the 
cylinder." 

At the solicitation of the Conseil de la 
Marine, P. Garnier constructed the Dynamo- 
meter, taking the primitive idea of Watt, 
adding many useful modifications, and using 
great care in its manufacture. After numer- 
ous trials it was judged superior to anything 
ye t known. The Council of Admiralty and the 
Minister of the Marine ordered all steamers 
to be provided with it, and allowed no engine 
to be received unless provided with this ap- 
paratus. This Dynamometrical Indicator is 
indispensable in showing the pressure of 
steam on the cylinders, and the vacuum ob- 
tained by its condensation. It gives the 
exact motive power' transmitted, as well as 
the amount of power lost by friction. Its 
undoubted utility made it universally adopted, 
and we owe to it our most interesting works 
on the power of machinery. 

At the Exposition of 1844, the jury, recog- 



63 



AMEBICAN HOEOLOGICAL JOUKNAL. 



nizing that " M. Paul Gamier is at the same 
time a skilful Horologist and a good con- 
structor of ingenious mechanical apparatus, 
wishing to reward, in this man, both the 
learned Horologist and skilful mechanic, 
award him the Gold Medal." 

Gamier now added a third to the preced- 
ing Indicators, and including both the others. 
This measured the total work of the steam, 
and the air in the cylinder of the engine. 
This instrument, already used in England by 
Prof. Moseley, lost its British origin through 
Garnier's improvements. He substituted Pon- 
celet's horizontal plate, with alternate move- 
ment, for Moseley 's planimetrical cone with 
continued movement, adding an arrange- 
ment for sketching curves and making 
diagrams. This last instrument was the 
cause of a sharp discussion with M. Lapointe. 
It was first applied, in France, to the pneu- 
matic cylinders of the atmospheric railroad 
of St. Germain, and it served to estimate 
precisely this power, in comparison with the 
steam and caloric engines, the rarification of 
the air, its compression, and the working of 
the valves. 

Gamier also invented a Horary Indicator 
for the safety of railroad trains. It was of 
clock-work, with a dial placed near the road, 
on which a hand told the minutes and 
returned to zero after each passing train, 
thus showing the time between two successive 
trains. This was in use at Columbia, at Or- 
leans, and on the Northern road. 

In the first trials of the Electric Telegraph, 
M. Gamier participated in the competition, 
and presented a system of telegraphy by 
means of a lettered dial. This was not a suc- 
cess ; but, thinking electricity might be em- 
ployed as a motive power to clocks, he turned 
his researches in that direction, and pro- 
duced a system of electric clocks, giving the 
hour synchronically, which were the first and 
only ones in Prance. For these he received 
a gold medal at the Exposition of 1849. The 
Council of Dock Yards proposed to the Min- 
ister of Public Works to adopt this system of 
electrical horology. The public applications 
of it in France were made simultaneously at 
Lille station, on the Northern Bailroad, and 
the stations from Paris to Chartres, and at 
St. Lazare. This system spread rapidly, and 



is in use in most of the public buildings. To 
the sympathy and friendship of the engineers, 
M. Gamier was much indebted for the intro- 
duction of his special apparatus for stations. 

A similar regulator gave M. Leverier the 
precise difference between the longitude of 
Paris and Havre. He arranged an automa- 
tic roller for the rapid and regular trans- 
mission of Morse's telegraphic alphabet. 
This is the indispensable complement to the 
American telegraph, for it will transmit mes- 
sages in several directions at the same time. 
For the perfection given to clocks and elec- 
tric telegraphs, he was awarded the medal of 
honor. At the Universal Exposition at Dijon, 
in 1858, he received a gold medal for a col- 
lection of his works. In Besancon, where 
Genevan and Swiss horology was carefully 
compared with French works, P. Gamier 
was chosen member of the jury, and, finally, 
in remuneration of his numberless services 
and useful and important inventions, was 
elected Chevalier of the Legion of Honor. 
He was a member of the Society for Encou- 
ragement of National Industry, and of the 
Civil Engineers. After the annexation of 
Savoy, he was chosen to look after the state 
of watch-making in Chablais and Fancigny, 
where this work was so well adapted to the 
habits of the people, and to their climate. 

After a careful study of their work, and 
comparison with that of Switzerland, Geneva, 
and Besancon, he gave a detailed report, 
which resulted in locating horological estab- 
lishments in French Savoy. 

Paul Garnier's life was a struggle of talent 
and labor against accumulated obstacles, be- 
fore which a less indomitable courage, and a 
less brilliant intelligence, would have failed. 
This struggle began in his earliest years, and 
ended only with his life. He learned in 
working; he won the esteem and affection of 
those for whom, and with whom, he labored. 
Struggling himself against ignorance, he 
raised a numerous and distinguished family, 
ever consecrating the largest part of his 
gains to the education of his children. Now 
his life is finished, having honored remem- 
brances, and universal regrets. 

Why are such examples so rare ? Because 
an inflexible rectitude was its governing 
power. Exact in his work, in his word, and 



AMERICAN HOROLOGICAL JOURNAL. 



67 



in his business, in its minutest detail — in the 
scrupulous and persevering care he gave each 
one of his works, we see how he inspired re- 
spect for his character, trust for his word, and 
love for his life. 

To such memories, a simple recital of their 
works is the most beautiful and fitting elegy. 
We have done this, because, for thirty years 
we have witnessed the works whose history 
we have sketched, thus briefly and imper- 
fectly. — Revue Chronometique. 



INBUSTBIAL EXPOSITION IN ALTONA. 



We are indebted to M. Morritz Grossmann 
for a description of the Exposition in Altona, 
as furnished the Industrie Zeitung, from which 
we make extracts, not having space for the 
article entire : 

" Among the French exhibitors the impor- 
tant manufactory of One'sime Dumas, at St. 
Nicholas d'Aliermont, France, received the 
Diploma of Honor for an excellent chronome- 
ter and a meter of peculiar construction. The 
renowned firm, Louis Breguet, Paris (also 
among the prize judges), exhibited the finest 
assortment of watches and scientific instru- 
ments. The watches were executed with 
astonishing care, and showed in their design 
the ingenious originality which has, for many 
generations, characterized this family. Among 
instruments for observation I noticed the 
Compteur a Point age (meter for pointing). 
The index, springing f second, bears on the 
end, beneath its perforated frame, a little 
printer's ink. Through this frame a needle 
point pierces (propelled by an outward 
spring) and by this means produces a dot 
upon the dial, which, after final observations, 
can be easily erased. Farther on we see a 
sphygmograph, an instrument designed to 
register the accelerations or irregularities of 
the beating of the pulse, thus greatly assist- 
ing the physician in his diagnosis. Yet fur. 
ther, amongl the Breguet collection, was an 
electro-magnetic telegraph, which needed no 
battery, and, as it at all times and without any 
preparation can be set in motion, it especially 
adapts itself for use on ship-board. The ex- 
plosive apparatuses (combustible and spring- 



ing) for the art of defence and for the 
management of mines, were finely planned 
and executed. The watch factory of H. H- 
Marten, of Freiburg, in Briesgau, exhibited 
an elegant assortment of beautiful anchor 
watches, and preparatory works, and single 
parts of the same, and well maintained its 
claim to the fame of gold medals received in 
former Expositions. A similar distinction 
was awarded Gustav Beeker, in Freiburg- 
Silesia, who merited it through a rich assort- 
ment of beautiful and praiseworthy articles, 
such as regulators with and without cases. 
His manufacture exceeds 7,000 pieces yearly. 
The collection of B. Haas, of BesanQon, 
showed an incredible number of watches and 
pocket chronometers. Watches in ivory 
cases with gold rims, watches with glass faces 
and backs, the dial even of glass, and the 
plates perforated, so one could see through 
the whole watch. One watch which opened 
and closed at the face, was pointed out by the 
exhibitor as entirely new and of his own in- 
vention, though it is known that this was 
patented two years ago in Birmingham. In 
a word, there was almost no variety of watch 
unrepresented, and this, to the non-connois- 
seur, lent an especial interest to the assort- 
ment. Less apparent lo the connoisseur was 
the fact, that the inner arrangement of works 
must follow determined principles, though 
they seemed various. The distribution of 
single parts here and there might almost 
awaken the belief that pendulums and spring- 
boxes had been proposed to constructors as 
fancy articles. Judging from these samples, 
it seems as if the manufactory of B. Haas, in 
spite of the remarkably scientific regulations, 
might not present the greatest success. Some 
tower-clocks deserving notice were exhibited 
by Harkensee, of Cutin, Hansen, of Altona, 
Wenle, of Bocken, near Hildsheim, and by 
Dokel, of Hanover. That of Hansen was dis- 
tinguished by a peculiar method of winding. 
A stationary warder controlling clock was 
exhibited by Ortling & G olze, of Neumunster, 
and a portable one of the same kind by Burk, 
of Schevermingen. Toys were scarcely repre- 
sented. Beside the objects cited, there were 
displayed (as everywhere on great occasions) 
a quantity of pendulum clocks, the occasional 
productions of workmen unaccustomed to their 



68 



AMERICAN HOROLOGICAL JOURNAL. 



manufacture. These were well done as to 
order and execution, still not above the level 
of common work. Finally, the Exposition 
was injured by the display of a medium 
assortment of Swiss and Paris manufactures, 
whose owner, a resident of Altona, or Ham- 
burg, had no other claim to them than that 
of having bought them. There are many 
who consider an Industrial Exposition only 
as an annual fair, so its higher aim is wholly 
perverted. The Horological section of the 
Altona collection was very deficient, for rea- 
sons formerly given, yet it had an influence 
to instruct, by means of comparing its own 
chronometer productions with the same de- 
partment of French industry. 

M. Grossmann. 



TRIFLES. 



Never, when taking a movement apart, drive 
the centre squarq arbor without supporting 
the bridge in some manner; it is usually very 
thin and easily bent, but almost impossible to 
restore to its original appearance when a 
bend has once got into the surface. 

Never open a watch case by inserting a 
screw-driver, and giving it a twist; it is a bad 
habit, for which there is no good excuse, and 
no workman will ever be guilty of " haggling" 
up a case, as such a practice is sure to do. 

Never scratch the number of your watch 
record on a case where it can be seen without 
the aid of a glass ; some reckless tinkers sc 
mar the beauty of a case in this way as to 
seriously irritate the owner. We once knew 
a journeyman who barely escaped a sound 
thrashing' from the owner of a watch, in 
which he had scratched his number in such 
awkward scrawling figures as to be visible at 
arms' length. 

Never put in a main- spring without ex- 
amining carefully whether any teeth or pinion 
leaves are broken or bent in the main, centre, 
or third wheel ; by so doing you will often 
save yourself the extra trouble of taking the 
watch down a second time to repair damage 
done by the recoil of the breaking spring. 

Never pour oil from the bottle into the oil- 
cup; it is wasteful, more being lost by drip 
than is used, besides the danger of taking up 



the fine dust adhering to the flange of the 
bottle. The neat, handy, economical way is 
to dip your oil wire to the bottom of the bottle, 
and it will bring away two or more drops, if 
raised quickly, which let fall into the oil-cup; 
repeat till you have taken out the requisite 
quantity. 

Never allow yourself, or any one else, to 
use the plyers, or tweezers, which are for 
watch work, in the repair of jewelry; they are 
sure to get a speck of soldering fluid (hydro- 
chlorate of zinc) on them, even the fumes of 
which at ordinary temperature will rust any 
steel work with which it comes in contact. 

Never . leave the wick of an alcohol lamp 
uncovered; the evaporation of the alcohol 
from the wick leaving the water behind (which 
is less volatile) renders it impossible to light 
it until the lamp is tilted so as to bring a new 
supply to the top, or the wick pulled up and 
cut off again ; both of which take time and 
consume patience. An extinguisher slij>ped 
over the wick prevents the evaj) oration, and 
the lamp is always ready to burn as soon as 
the match is applied. 



ANSWERS TO CORRESPONDENTS. 

G. N. L., Baldwinsville, N. Y. — The very 
large proportion of watches coming for repairs 
which bear indelible marks of carelessness 
and incompetency, is evidence that those 
" new to the business " are not the only ones 
who need instruction. 

To begin at the beginning, a good bench is 
indispensable ; for no one can do as well with 
poor accommodations as if well fixed. A 
chest of drawers for tools is an important 
adjunct ; tools should be in good order ; one 
pair, at least, of plyers should be lined with 
brass, to handle polished pieces without 
marring them. You are now ready to take 
down, examine, put to rights, and clean a 
watch — supposing m this case that no new 
parts are required. First see that the hands 
and motion work are free ; examine the 
escapement — the depth of lock the tooth has 
on the pallet ; look to the safety action that 
it is free, and when forced against the roller 
that the wheel tooth does not get upon the 
impulse face of the pallet ; examine the end- 



AMEKICAN HOROLOGICAL JOURNAL. 



69 



shakes of all pieces — escapement and train ; 
depths of wheels and pinions ; see that the 
pinions are all secure in the wheels ; that 
jewels, holes, and end-stones are firmly set ; 
see that the main spring is the proper width, 
strength, and length ; and as we meet with 
so many springs that are not correct, it is 
evident that somebody needs instruction on 
this point. 

The arbor should be one-third the'diameter 
of the barrel inside ; the spring should fill 
the barrel one-third, and if a going barrel, 
should be of such thickness as to admit 
thirteen coils — fusee watches requiring ten to 
twelve coils, according to the calculations. 
Occasionally a watch requires - a variation 
from the regular rule, stronger or weaker, as 
the case may be. All bars, bridges, stop- 
work, etc., should be taken off ; the fusee 
and great wheel should be taken apart and 
thoroughly pegged ; the barrel-bridge (if a, 
going barrel watch) must be taken all in 
pieces. After pegging the pinions and holes, 
and removing all old oil from pivot§, jewels, 
etc., with the pith, wash it, using fine Castile 
soap ; rinse in clean water, and put it in 
best alcohol, taking it out as soon as the 
washing process is completed, and drying 
with a clean soft cotton or linen rag ; after 
which go over with a soft clean brush, to 
remove all particles of lint. To give the 
gilding the best appearance, brush in circles, 
breathing on the work occasionally ; but 
little brushing, however, will be necessary. 
A very pernicious practice prevails with many 
workmen, of putting their dirty work, all 
sineai'ed with oil, directly in the alcohol ; the 
result being a change in the complexion of 
the gilding ; and if two pieces are left toge- 
ther you have tivo shades, varying from the 
original. 

In putting up, be careful to use no more 
oil than is necessary, and to put it just where 
required — the barrel bridge and click being 
parts that show " slobbering" most of any. 
If the proper quantity is put just where 
wanted, none ever reaches the click; and cer- 
tainly nothing looks worse than oil " stewing" 
out, smearing bridge and click. If an ad- 
justed watch, and no damage has happened 
to balance pivots, or spring, disturb noth- 
ing except to put in beat, if not so already. 



If a common or medium class watch, take off 
the spring and test the poise of the balance; 
if not correct, make it so. Put the spring on 
an arbor in the turns, and with a bow rotate 
to see if it is true in the spiral and flat ; if 
not, correct it. To get your spring parallel 
to the balance without bending, make the hole 
in the stud parallel to the cock, and file a pin 
to fit the hole ; then flatten one side similar 
to a flat-faced cylindrical ruby pin, until it 
will enter, with the spring in its place, nearly 
as far as without it ; cut off the point to pro- 
per length — rather short — and round it off 
with a fine file ; mark and cut off the pin, 
leaving a good length of head to get hold of. 
Now a little twist of the pin will put the 
spring in any position, and you can in a mo- 
ment get it perfectly parallel to the balance, 
without bending. Now set the watch going, 
with the regulator pins close on the spring, 
and the regulator well back to slow on the 
index ; and if it does not go very near time, 
alter the spring until it does so, with the regu- 
lator in the position referred to. The object 
of this is to get the most uniform rate pos- 
sible, and it is attained with the regulator as 
near the stud as possible. If the coils are 
cramped, take the spring from the balance 
again, without unpinning from the stud, and 
put them in their places on the cock, and 
bend, or open the coils, as may be necessary 
to make the collet concentric to the staff hole. 
If the spring is greasy, or in any way dirty, 
dip it in benzine or ether a few seconds — the 
former is best — and you have it perfectly 
clean. After you have put it in beat, and are 
sure that the balance will not have to be 
taken out again, put oil to the holes, a little 
only to the pallets — none to the fork ; if a 
duplex escapement, oil must be put to roller 
— none to impulse pallet ; a chronometer re- 
quires oil only to pivots ; set going and your 
watch is "in order." 

Now, many will say that this is too much 
work for the price of cleaning ; certainly it is, 
and you must make the price according to 
the time spent upon it. It is cheaper to the 
customer if you charge double 1 price for your 
time, than if done in the usual style of dry 
brushing and without the corrections. 

W. W. S., Danville, 111. — The reduction of 
alloys in the reguline or metallic form is a 



70 



AMERICAN HOKOLOGICAL JOURNAL. 



matter of great uncertainty, and is a branch 
of the subject of electro-metallurgy, which 
has not been reduced to fixed and definite 
laws. The action of the voltaic current, in 
connection with the nature of the surfaces 
acted upon and the temperature of the solu- 
tion, all together, or separately, present con- 
ditions which seem to elude the researches of 
the scientific chemist, as well as severely per- 
plex and vex ihe practical gilder, it is gener- 
ally understood that the decomposition of the 
various salts is attributable to the secondary 
action of hydrogen, termed electro chemical 
decomposition, and it is well ascertained 
that different metals, or even the same metals 
under different circumstances, evolve hydro- 
gen from the same solution with various facil- 
ities. It is natural to suppose that if it be 
a law, as some assert, that the voltaic circuit 
is invariably completed in that mode which 
offers least resistance to the passage of the 
force, that there are some cases where the 
nature of the negative plate, on which the re- 
duction of the new deposit takes place, influ- 
ences the result ; this is actually found to be 
the case, and the difficulty you have experi- 
enced seems to be a similar case ; for some- 
times in the self same solution, when a smooth 
negative plate is used the circuit would rather 
be completed by reducing the metal, but when 
a rough plate is employed, like your low 
quality chain, by the evolution of hydrogen. 
This most interesting fact is in no instance 
better shown than in a slightly acidulated so- 
lution of sulphate of zinc, from which bright 
zinc will go freely down on smooth platinum; 
whilst from platinized platinum (crystallized) 
the hydrogen would be evolved. This ex- 
periment may be varied in a hundred analog- 
ous ways, with results at one time in favor of 
the evolution of the gas, at another by the 
decomposition of the compound; but the exact 
relation which various metals perfectly di- 
vided in the solution bear to each other, or 
even to themselves in different solutions, or 
in the same solution at different temperatures, 
is very difficult exactly to determine. As a 
general principle, to obtain a deposit of two 
or more bodies on any negative pole you 
must use a quantity of the voltaic force more 
than sufficient to reduce the elementary sub- 
stance from the compounds most readily de- 



composed ; usually you will find that the cur- 
rent will pass through the road which presents 
the least obstacle, whether it be solid or fluid, 
elementary or compound, great or small. 

Ordinarily, the smoother the surface, the 
more favorably the deposit will take place 
upon it ; from a rough surface the hydrogen 
has a greater tendency to be evolved, and the 
electric current must be suited to these vary- 
ing circumstances ; but in general a feeble 
current only is required, and the surface of 
the positive pole exposed to the action of the 
solution should not exceed the surface 
of the object to receive the deposit, and the 
quantity of electricity allowed to pass may 
and must be regulated to the utmost preci- 
cision, by allowing more or less of the positive 
pole in contact with the solution. To con- 
duct this process with the greatest economy 
of time, the quantity of electricity should be 
so regulated to the strength of the metallic 
solution that the hydrogen is kept below 
the point of evolution from the negative pole; 
for you must always bear in mind, that the 
evolution of hydrogen is attended with evil, 
as the deposit will then be in one of the 
finely divided states, or even as a black 
powder. During the process, particularly 
if the object have a rough surface, it is a good 
plan to remove it from the solution before 
the completion of the process, and rub it with 
a hard brush and a small quantity of whiting 
or rotten-stone, and well wash it ; by these 
means any finely divided metal will be 
removed, and the gold will be deposited in a 
very even manner. This cleansing will not 
be required if the deposition takes place 
very slowly, from the auro-cyanide solution. 
If the precipitated layer be very thiu, the 
color will be greenish yellow ; when thicker 
it will be the color of pure metal. The state of 
the surface of the reduced gold^aries with 
the rapidity of the process, in relation to the 
strength of the metallic solution ; if reduced 
very slowly it will assume the beautiful frosted 
appearance of dead gold. If deposited more 
rapidly, the surface will have a brighter ap- 
pearance ; if still more rapidly the surface 
will again begin to be brown, and quicker 
than this the operator must not conduct his 
process, for then the spongy (or crystalline) 
deposit begins. 



AMERICAN HOROLOGICAL JOURNAL. 



71 



The probabilities are that the great extent 
of surface which your chain presented to the 
action of the solution, compared with the 
surface presented by the opposite pole, in 
some way modified its action. Had you pro- 
portionally increased the size of the positive 
pole, which would in effect have increased 
the electric current passing, perhaps you 
might have got a deposit simultaneously of 
the fine gold and the alloy. Then again, the 
surface of the chain may have been in such 
condition (roughened) as to materially change 
the character of the deposit upon it. The 
results of the combinations of invisible and 
unknown conditions are so uncertain as to 
defy any positive directions in any given case. 
A. M. B., Ioivi. — Marion is only fifteen 
minutes from Maiden Lane — lying at the 
west side of Jersey City. Yes ; the Watch 
Factory is like the engraving on the last page 
of the Journal, though you cannot get a cor- 
rect idea of its beauty from any drawing. 
The main building is 253 feet in length, three 
stories in height, besides the basement, and 
is built entirely of iron and glass — light and 
ventilati on being primary considerations in 
its construction. "We cannot give you a 
detailed description of the machinery, as that 
would occupy several complete Nos. of the 
Journal, but when you come to the city we will 
endeavor to show you the practical details of 
manufacturing watches by machinery. Your 
third query we have no hesitation in answer- 
ing in the affirmative, fully believing that the 
United States Watch Company have produced 
movements fully equal to any made in the 
country. The prices of their movements are 
all the way from $8.75 to $300, embracing 
sixty-four qualities. 

"Damaskeening" is simply an improved 
method of finishing nickel, by the aid of ma- 
chinery, whereby its beauty is not only 
greatly enhanced, but entirely overcomes the 
principal objection to the use of that metal 
for watch movements — that of tarnishing. 
This process is so far a secret with this Com- 
pany. 

Having replied to your questions, permit 
us to say a word of encouragement to the 
young men who are just commencing in life. 
Mr. F. A. Giles, the President of the United 
States Watch Company, as well as the head 



of the house of Giles, Wales and Co., is a 
living evidence of the fact that honesty and 
fair dealing, coupled with energy and frugal- 
ity, are a much surer guarantee of success in 
life than inherited wealth. Having been left 
an orphan at an early age, and being the 
eldest of a family of children, he was not only 
dependent upon his own exertions for self- 
support, but contributed largely to the sup- 
port of the rest of the family ; and it is to this 
very fortuitous circumstance that he owes the 
development of those traits of character — 
that indomitable energy and perseverance — 
that is the sole secret of his success as a busi- 
ness man. And Mr. Giles is but a type of a 
class of men who are to-day ruling the desti- 
nies of the world, as statesmen and men of 
business, and who are in the fullest sense of 
the word self-made men. 

Mr. Wales, the head of the salesroom of 
the house of Giles, Wales & Co., is no more 
indebted to the influence of powerful friends 
than his partner — having won his way to an 
enviable position as a business man strictly 
on his merits — and never fails to entertain a 
kindly feeling for, or to extend a helping 
hand to, any deserving young man. As Mr. 
Wales never received a dollar of assistance 
from any one after he was eight years of age, 
we are of opinion that most young men have 
as good a starting-point in life as he had. 

And, while on this subject, we will instance 
another case — that of Mr. C. L. Krugler, of 
the firm of Quinche & Krugler, 15 Maiden 
Lane, who commenced his mercantile career 
as a peripatetic vender of matches — and 
although he is now an importer of watches, 
never blushes at the mention of his modest 
start in life. 

An Apprentice wants to know the proper 
height for a work-bench ; says his master 
puts him at one so high as to make his shoul- 
ders ache. 

We incline to the opinion that his master 
is correct. Of course we don't know exactly 
the feet and. inches that the lad is, or the 
bench should be ; but have found this rule 
about correct: Any stick, the size of a cane 
for example, held under the arm, and paral- 
lel with the floor, as close up under the shoul- 
der as possible, the arm being held down by 
the side, should just clear the top of the 



72 



AMERICAN HOROLOGICAL JOURNAL. 



bench vise ; the same rule to apply whether 
working at a standing or sitting bench. The 
pernicious tendency of young persons is to 
work at a bench too low down, thereby in- 
ducing in themselves a stoop of the shoul- 
ders, injurious to health, and symmetry ; to 
health, because the lungs — the very citadel 
of life — are cramped, and restricted in their 
muscular action (analogous to the opening 
and shutting of a bellows); and to symmetry, 
because a round-shouldered, hump-backed 
man is not "in the image of his maker." 
Every young man should know, or be taught, 
that when the arms are elevated so as to be 
on a line with the shoulders, the shoulders 
themselves are thrown back, the chest is free 
from side pressure, the lungs can be fully in- 
flated, the head maintain a natural position, 
even where the eye-glass is in use, and the 
spinal column (back bone) is quite upright; 
which, by the way, is a very important thing 
to be remembered. The position a person 
assumes, who has to sit all day, and day 
after day, is of the greatest moment as re- 
gards their comfort and ease. No position 
is more fatiguing than the "bow-backed." 
With the back straight up and down — or, 
mathematically expressed, the weight direct- 
ly over the base — is the easiest, most grace- 
ful, and healthiest position, and should be 
acquired by all. At first it may be a little 
irksome, but persevere, and you will reap the 
benefit during your whole lifetime. 

E. C, S., N. J. — For information in regard 
to London Horological Journal, address Secre- 
tary of British Horological Institute, London. 

B@„» We are very anxious for a few copies 
of Nos. 4 and 5, Vol. I, of the Horological 
Journal, and will pay a liberal price for them. 

AMERICAN HOROLOGICAL JOURNAL, 

PUBLISHED MONTHLY BY 

O - IB. MILLER, 

229 Broadway, JT. T., 
At $3.50 per Year, payable in advance. 

A limited number of Advertisements connected 
with the Trade, and from, reliable Houses, will be 
received. 

fi>§P°> Mr. J. Herrmann, 21 Northampton 
Sjuare, E. G, London, is our authorized Agent 
for Great Britain. 

A'l communications should be addressed, 
G. B. MILLER, 
P. 0. Box GTlo, New York. 



EQUATION OF TIME TABLE. 



GREENWICH MEAN TIME. 



For September, 1870. 



X 




Sidereal 










<x> 




Time 


Equation 






Sidereal 


& 




of 


of 


Equation 




Time 


a 


t»ay 


tha S3mi- 


Time to be 


of 


for 
One 
Hour. 


or 




of 


diameter 


Subtracted 


Time to be 


Right 


v. 


Mori. 


Passing 


from 


Added to 


Ascension 


>> 




the 


Apparent 


Mean Time. 


of 


P 




Meridian. 


Time. 






Mean Sun. 






s. 


M. s. 


M. s. s. 


H. M. s. 


Th. 


1 


64 41 


6.10 


6.11 ! 0.782 


10 41 47.28 


Fri 


2 


64.37 


25.00 


25 01 0.794 


10 45 43.83 


Sat 


3 


64.33 


44.19 


44.21 0.806 


10 49 40.38 


Rn. 


4 


64 29 


1 3.67 


1 3.70 0.817 


10 53 36.94 


M 


5 


64.26 


1 23.42 


1 23.44 0.828 


10 57 33.49 


Tn. 


6 


64.23 


1 43 40 


1 43 42 0.838 


11 1 30.04 


W 


7 


64 20 


2 3 60 


2 3.63 0.847 


11 5 26.60 


Th. 


8 


64 17 


2 24 01 


2 24 04 0.855 


11 9 23.15 


Fri 


9 


64.15 


2 44.59 


2 44.62 0.862 


11 13 19.70 


Sit 


10 


64.13 


3 5 32 


3 5.35 0.868 


11 17 16.25 


Sn. 


11 


64.11 


3 26.18 


3 26 23 0.873 


11 21 12.81 


M 


12 


64.09 


3 47.14 


3 47.20 0.877 


11 25 9.36 


Tn 


13 


64 08 


4 8.1* 


4 8.26 0.880 


11 29 5.91 


W 


14 


64 07 


4 29.31 


4 29.38 0.882 


11 33 2.46 


Th 


15 


64.07 


4 50.48 


4 50.56V 0.885 


11 36 59.02 


Fri 


16 


64 06 


5 11 66 


5 11 74 0.883 


11 40 55.57 


Sat 


17 


64.06 


5 32.84 


5 32.92 0.883 


11 44 52.12 


Sn. 


18 


64 06 


5 53 99 


5 54 08 0.882 


11 48 48.67 


M 


19 


64.07 


6 15.10 


6 15.20 0.880 


11 52 45.22 


Tn 


•2(i 


64.08 


6 36 16 


6 36.27 0.877 


11 56 41.78 


W. 


21 


64 09 


6 57.13 


6 57.24 873 


12 38.33 


Th 


22 


64.10 


7 18.01 


7 18.12 0.868 


12 4 34.88 


Fri 


23 


64 12 


7 3^.79 


7 38.90 0.863 


12 8 31.44 


Sit 


24 


64.14 


7 59.42 


7 59.53 , 0.857 


12 12 27.99 


Sn 


25 


64.16 


8 19.89 


8 20.01 1 0.851 


12 16 24.54 


M 


26 


64.19 


8 40.21 


8 40.33 0.844 


12 20 21.09 


Tn 


27 


64 . 22 


9 34 


9 0.47 0.836 


12 24 17.65 


W 


28 


64.25 


9 20.27 


9 20.40 , 0.827 


12 28 14.20 


Th 


29 


64.28 


9 40.00 


9 40.13 0.818 


12 32 10.75 


Fri. 


30 


01.32 


9 59.49 


9 59.62 [ 0.808 

1 


12 36 7.30 



Mean time of the SemidiamHer pissing may be found by sub- 
tract ig 0.18 s. from the siiereal tiau. 

The S8mldiamet3r for m^an neon may be assumed the same as 
that for apparent noon. 

PHASES OF THE MOON. 

D II. M. 

J First Quarter 2 1 57.9 

@ FnllMwn 9 10 11.6 

( Last Quarter 17 13 29.9 

% New Moon 24 18 31.0 

D. H. 

( Apogee 14 7.0 

( Perigee 26 79 

Latitude of Harvard Observatory 42 22 48 . 1 

h. M. s. 

Long. Harvard Observatory 4 44 29.05 

New York City Hall 4 56 0.15 

Savannah Exchange 5 24 20 572 

Hudson, Ohio 5 25 43.20 

Cincinnati Observatory 5 37 58.062 

Point Conception 8 142.64 

APPARENT /PPAKE>"T MERID. 

R. ASCENSION. DECLINATION. PASSAGE . 

D. H. M. S. / „ H. M. 

Venus 1 9 7 9.82 .. .+17 12 11.2 22 26.3 

Jupiter... 1 5 31 52.46.... +22 43 38.1 18 47.4 

Saturn... 1 17 25 13.15. ... -22 750.8 6 42.3 



AMERICAN 





Vol. II. 



NEW YORK, OCTOBER, 1870. 



No. 4. 



CONTENTS. 

Practical Education, 73 

A Suggestion to Watch Manufacturers, ... 76 

Taktn-g ix Woke, 77 

Heat, 78 

Explanation of Astronomical Teems relating to 

Time, 81 

The Leyer Escapement, 83 

Dialing, 87 

Patience, 92 

Gaelic Juice vs. Magnetism, 93 

N. Y. Watch Co., 93 

Staking Tools, 94 

Answers to Correspondents, 9-1 

Equation of Time Table, 96 

* * * Address all communications for Horological 
Journal to G. B. Miller, P. 0. Box 6715, New York 
City. Publication Office 229 Broadway, Room 19. 



PEACTICAL EDUCATION. 



In the infancy of the world, knowledge was 
rare; in its youth, it was a " dangerous thing." 
Wise men were few, and fewer the sages who 
held even one of Nature's hidden laws. The 
Alchemist — regarded almost as a wizard — 
concealed carefully his discoveries from the 
public gaze. He pursued but one object — the 
conversion of the base into precious metals ; 
hence every occurrence which he deemed 
irrelevant to his purpose was entirely ne- 
glected, or foolishly philosophized upon. He 
sought to teach Nature, rather than follow her 
gui dings; therefore it cannot surprise us that, 
under his auspices, science made little prog- 
ress. Now, as a Chemist, he proclaims to 
the world the results of his profoundest re- 
search — gaining increased power and influ- 
ence from this diffusion of knowledge. 

The skilful artisan is no longer made 
famous by the few specimens of his work, 
laboriously wrought in secret by his own hand, 
lest others, seeing, should appropriate the 
results of his arduous thought; but he speaks 
to all peoples by the creation of great factories, 
and the numberless specimens of his craft 
produced by these his mighty servitors. By 
lectures he teaches the parents ; in schools he 



instructs the children ; through the press he 
informs the world ; and by these means he 
gains wealth and influence, and thus knowl- 
edge becomes power. In the rudimental con- 
dition of art or science, isolated facts — some- 
times the result of accident, but oftener of 
systematic observation — are the first rays 
which penetrate the gloom obscuring them. 
Systematic classification of these facts are the 
tints of dawn which brighten the Eastern sky. 
Then some master mind breathes on this 
cumulous mist — the clouds disperse, and there 
bursts upon the world the glorious sunlight 
of a new science. 

Let us glance at the developments of Teres- 
trial Magnetism. At first iron alone, in its 
various forms, was considered magnetic ; and 
nothing beside was thought susceptible to its 
influence. Soon it was seen that other sub- 
stances were acted upon, though in different 
ways. These were called dia-magnetics. A 
heavy bar of solid glass, which is eminently 
dia -magnetic, being suspended, moving freely 
between the poles of a horse-shoe magnet 
(called a magnetic field), gradually assumes a 
position at right angles to the current passing 
through the field. Being replaced, it again 
assumes the same position, showing an op- 
posite action to a magnetic substance under 
the same circumstances. Other experiments 
on solids and liquids, as well as on all the 
known gases, pointed unerringly to the law 
that all substances are either magnetic or dia- 
magnetic. The particles of a magnetic body 
are attracted to, while those of dia-magnetic 
are repelled from, each other ; and these 
peculiarities are retained by each substance 
in all conditions and combinations. The 
action of any compound under magnetic in- 
fluence is exactly in accordance with the pre- 
ponderating substance. Thus water (dia- 
magnetic), holding a solution of iron (magne- 
tic), assumes position in the magnetic field in 
accordance with the strength of the solution; 



74 



AMERICAN HOBOLOGICAL JOURNAL. 



being magnetic, if the iron preponderates ; or 
dia-magnetic, if the water exceeds. 

The mechanical arts and the science of 
mechanics are no exception to the same cu- 
mulative growth. Philosophers did not dis- 
cover the lever, the wheel, the wedge ; poor 
ignorant laborers were the first discoverers — 
their necessities were the mother of their in- 
ventions; these powers, in some s : mple form, 
were daiJy used, and their prodigious effects 
noticed, and their use spread frcm 
hand to hand; new adaptations multiplied; 
facts regarding their application were remem- 
bered; certain re ations were noticed to pro- 
duce invariably certain effects. At length 
these effects were generalized and arranged ; 
and at once the law, certain and clear as the 
sunlight, was deduced. Experiment became 
the foundation — fact the superstructure 
theory, only the scaffolding of the perfected 
temple. As soon as the system was adopted 
of tracing causes from their effects, experi- 
mental science advanced with rapid strides. 
From its lofty abode in the time of Coperni- 
cus and Galileo, it has since descended and 
become the household god of all in our land ; 
the cause of the conveniences and comforts 
of our existence. Had the first man who 
moved a stone more ponderous than himself, 
by means of a lever, concealed from his fellows 
the means by which he accomplished it, who 
can say how long the world might have 
remained in ignorance of the complete sci- 
ence of mechanics ? 

So it may be with our own craft, if each 
gives to the world the facts gathered b} r him- 
self ; though they be in themselves insignifi- 
cant, yet their accumulation from all sources, 
and all pointing in one direction, may lead to 
the discovery of a valuable law. For example, 
suppose every watchmaker were to observe 
carefully when, how, and under what circum- 
stances every mainspring was broken that 
came under his observation. Whether at the 
time the temperature of the weather was hot 
or cold ; was the condition of the atmos- 
phere unusually electrical or otherwise — 
cloudy or clear ; was the wind from the 
north, scuth, east, or west ; the moon full, or 
at first or last quarter ; day or night ; wet or 
Cvj ; the height of the barometer ; was the 
spring in motion or at rest ; coiling or un- 



coiling ; was it oiled much, little, or not at 
all ; was it tempered blue or yellow ; had it 
been long in use, or was it new ; was the user 
in health, or ill ; in anger, or at ease ; his 
habits active, or sedentary ; and a hundred 
other little facts gathered in various sections 
and in various countries. Who can say that 
from some such aggregation a law might not 
be deduced by which we might determine 
what now no man pretends to know — namely, 
why a mainspring breaks ? 

By the systematic observation of facts 
of any kind, and the fullest diffusion of 
them among those who are interested, no one 
knows how soon the accumulated mass may 
be seized by some master hand and moulded 
into form. 

Although, in order to be a practical work- 
man, it is not necessary to tread the stately 
measures of Euripides — with Horace, to cele- 
brate the beauteous Roman dames, or with 
Juvenal, to " shoot folly as it flies" — yet, 
while we are endowed with a higher nature 
— with understanding as well as senses — with 
faculties more exalted, and enjoyments more 
refined than any to which the bodily frame can 
minister — let us pursue such gratifications ra- 
ther than those of mere sense, fulfilling thus the 
most exalted ends of our creation, and obtain- 
ing a present and future reward. Let us mark 
the practical applications of science (which in 
its most comprehensive sense means knowledge 
reduced to a system) to the occupations and 
enjoyments of all, beginning with the greatest 
portion of every community, the working 
classes. 

The first object of every one depending 
on his own exertions is to provide for his 
daily wants, for this includes his most sacred 
duties to himself, his kindred, and his country. 
Though in performing it he is influenced by 
his necessities or interests, yet it renders him 
the truest benefactor of his community. The 
hours devoted to learning must be after the 
work is done, for independence requires first 
a maintenance for himself and those depend- 
ing on him, ere he earns the right to any in- 
dulgence. The progress made in science 
helps every trade or occupation. Its neces- 
sity to the liberal professions is self evident, 
but other departments of industry derive 
hardly less benefit from the same source. To 



AMERICAN HOROLOGICAL JOURNAL. 



75 



how many kinds of workmen is a knowledge 
of mechanical philosophy necessary ? To how 
many others does chemistry prove useful ? 
To engineers, watchmakers, instrument-mak- 
ers, a ad bleachers, these sciences are essential. 
Are those who work in various metals the 
less skilful for knowing their nature, their 
relations both to heat and other metals, and 
to the gases and liquids with which they 
come in contact ? If a lesson be learned by 
rote, the least change of circumstances puts 
one out. Cases will always arise where a 
rule must be varied to apply ; so if the work- 
man only knows the rule, without the reason, 
he will be at fault when required to make a 
new application of it. Another use of such 
knowledge is, that it gives every man a chance, 
according to his talents, of becoming an im- 
prover of his art or trade, or even a discoverer 
in the sciences connected with it. He daily 
handles the tools or materials with which new 
experiments are to be made — daily sees the 
operations of Nature in the motions and pres- 
sure of bodies, or their actions on each other ; 
and his chances are much greater, apply- 
ing his knowledge to new and useful ideas, to 
see what is amiss in the old methods, and, 
taking advantage of it, improve and renew 
them, and he may make discoveries which may 
directly benefit himself and mankind. To 
pass our time in the study of science, to learn 
what others have discovered, and to extend 
the bounds of human knowledge, has, in all 
ages, been called the happiest of human 
occupations. But it is not necessary a man 
should do nothing but study known truths, 
and explore new, to earn the title of philos- 
opher, or lover of wisdom. Some of our 
greatest man have been engaged in the pur- 
suits of active life. An earnest devotion of 
the most of our time to the woi'k our condition 
requires, is a duty, and indicates the possession 
of practical wisdom. He who, wherever his 
lot may be cast, performs his daily task and 
improves his mind in the evening, richly de- 
serves the name of a true philosopher. It is 
no mean reward to become acquainted with 
the prodigious genius of those who have 
almost exalted the nature of man above this 
sphere, and to discover how it comes to pass 
. "by universal consent, they hold a sta- 
tion apart, rising over all great teachers of 



mankind, and named reverently, as if New- 
ton and Laplace were not the names of mortal 
men." By means of the laws of gravitation 
and the movements and changes of the celes- 
tial bodies, we have taken " note of time," if 
only b}^ its flight. 

In diffusing valuable information it is by 
no means necessary that a person should be 
learned, or even educated ; if they have some 
complete idea, well thought out before they 
attempt to utter it, there need be no fear of 
failing in expression ; for this thinking has 
been done in language, and the expression of 
the idea is only thinking aloud. Education 
is desirable ; every species of knowledge is of 
service, and our hope for the future is to have 
it attainable by all. By education we do not 
mean a classical education ; in fact we fully 
believe it a waste of time and money in a 
person who does not intend to make litera- 
ture his profession. We believe that every 
man's education should have direct reference 
to the occupation he chooses, or that is chosen 
for him, and that all the mental discipline he 
wishes to undergo should be in the line of 
that profession. The study of the classics to 
a mechanic are a waste of mental energy. An 
equal amount of mental training can be had 
by studies bearing directly on his business. 
The whole line of mathematical studies are 
eminently calculated to discipline, the mind, 
foster deep thinking, and cultivate the most 
rigid exactness in diction as well as thought, 
and every acquirement in that branch is a 
direct stepping-stone to the attainment of 
eminence in any mechanical calling. 

Three words comprise all that is necessary 
for a mechanical education, viz., reading, writ- 
ing, and arithmetic. Beading being the means 
of acquirement of every species of general in- 
formation from all accessible sources ; Writ- 
ing, the correct use of language by carefully 
studying the best examples within our reach, 
and Arithmetic embraces the whole course of 
mathematical studies. A large proportion of 
the time spent by collegiate students is lost 
— or at least the benefits derived are very in- 
direct, if not questionable. How many grad- 
uates can be found who know or care a straw 
for Plato, or iEsckylus, or what do they re- 
member of Horace, except a few stale quota- 
tions ? Indiscriminate classical must, sooner 



76 



AMERICAN HOROLOOICAL JOURNAL. 



or later, give place to technological education. 
No man's life being long enough to acquire all 
knowledge, the consequence will be, devotion 
to particular branches of learning. " To that 
complexion must we come at last," and the 
sooner we set ourselves about organizing the 
proper means to secure such desirable results, 
the better. 

We trust the day is not far distant when 
the colleges of the past will give place to 
technological institutes whose efforts will 
be mainly in the direct education of its stu- 
dents in the practical pursuits of life, rather 
than a devotion of their energies to the 
study of the dead languages. The mental 
discipline is fully as severe in the one case as 
the other, and in technological education it 
leads to practical results. In short, the truths 
of modern science, and a familiarity with 
mechanical principles, are of much greater 
importance to-day, than a familiar knowledge 
of the loves, and intrigues, and warfare of all 
the heroes of the past ages. 

"Why can we not have Horological Institutes 
as well as Medical'? and have "Anxtomical 
Lectures before the class," with " free clinics 
every Friday, and treatment of the poor 
(watches) gratis ? " a " Museum of Morbid 
Anatomy" (subjects are plenty), "Chemical 
and Philosophical Experiments," " Illustra- 
tion of the use of Instruments " (tools), call 
our best workmen " Professors," and our ap- 
prentices " Students," have "Theses" read on 
various subjects, grant "Diplomas," and class 
Horologists among the liberal professions ? 



A SUGGESTION TO WATCH MANUFACTURERS. 



o- 



tf@„» "We confidently expect to be able to 
present to our readers, next month, an article 
from Mr. Grossniann. In his letter of June 
23d, he proposed to forward the next week, 
drawings of his Mercurial Pendulum ; but it 
failed to come to hand, which is probably 
attributable to the fact that, in consequence 
of the war between Prussia and France, the 
mail service with all the German States has 
beeu very much deranged. Undoubtedly he 
will also, in reply to " Clyde," in the Au- 
gust No., support the propositions laid down 
in his former article on the Mercurial Pen- 
dulum. 



The growing popularity of American 
watches with the watch-carrying public — 
thereby rendering it incumbent upon all 
dealers to make them a part of their stock — 
is raising the question among the most in- 
telligent workmen as to which of the various 
manufacturers really produce the most reli- 
able time-piece ; and which one he can con- 
scientiously, and with the most interest to 
himself, recommend to his customers. By 
"interest to himself," we do not mean the 
watch on which he makes the most immedi- 
ate profit. The most important consideration 
to the thoroughly practical mechanic who 
takes a pride in giving to his customer the 
nearest possible approach to mechanical per- 
fection in the time-piece he sells him, is, what 
watch will give the best results in that direc- 
tion, and give to him the best reputation as 
a dealer. 

To watchmakers, certificates, even from 
eminent men, prove very little, as, from the 
very nature of the case, the testimony of the 
wearer of a watch is confined to a single one, 
and all the certificates any manufacturer 
publishes must necessarily bear a very small 
proportion to the entire number manufac- 
tured. Besides, few, if any, have the means 
of making correct comparisons, even had 
they the disposition to do so. The compari- 
son of a watch to-day with any standard 
authority, and a comparison with the same 
authority at the expiration of twelve months, 
and showing very good results, proves noth- 
ing ; for possibly there might not have been 
any period in the intervening time when the 
comparison would have resulted so favorably. 
A comparison of rates with the best chro- 
nometers or regulators at the command of 
the watchmaker is eminently satisfactory, 
but they are not infallible ; in fact, they in- 
variably have a daily rate of gain or loss, and 
frequently errors, either concealed from the 
public, or not. known to the watchmaker him- 
self, and nothing short of a frequent observa- 
tion of the heavenly bodies will give a reli- 
able indication of the real performance of the 
watch. 

Again, one watch selected from a hundred 
may give results bordering on the marvellous, 



AMERICAN HOROLOGICAL JOURNAL. 



77 



and still the other ninety-nine be very indif- 
ferent time-keepers ; the average performance, 
perhaps, being much below the same number 
of another maker, who, on a single watch, 
could not show as high a degree of perfec- 
tion as his competitor. 

The highly creditable display of American 
watches, now on exhibition at the Fair of the 
American Institute in this city, is well de- 
signed to add to the growing interest felt in 
this branch of national industry; but it occurs 
to us that something more than the mere 
display and extensive advertisement of goods 
is required; and that is, that competitive trials, 
in some form, should be instituted. Just now T 
su'di trials should be conducted so as not 
oidy to secure an honest verdict, but at the 
same time satisfy the public of the thorough- 
ness and practical nature of the tests. It may 
not be easy to fully prescribe the details, but 
as tending in that direction we make these 
suggestions : 

1. It should, of course, be a condition that 
the watches entered were entirely of Ameri- 
can manufacture. 

2. It would be manifestly unfair that 
watches that merely chance to possess re- 
markable properties should be selected from 
a large number, and which were not a fair 
sample of the average manufacture ; for then 
the advantage would be with the largest pro- 
ducer. A definite number only on the part 
of each maker should be entered, and these 
numbered in rotation before springing — none 
being duplicates of other numbers. Or, per- 
haps it would be better to dispense with these 
conditions by presenting a certain number on 
the part of each maker, from which a random 
selection should be made by the appointed 
judges. 

Of course the watches of the different 
makers should be of the same price, and 
might include all the grades that could fairly 
enter into competition from each of the fac- 
tories. The object being to determine who 
places the most reliable time-piece on the 
market, it would be manifestly proper that 
they should be taken as they are offered to 
the public, and not as they might be gotten 
up for a competitive trial. On watches 
prepared for trial, it would be expected 
each maker would bestow the highest 



skill in adjusting, even though it should 
considerably raise them above the average 
character. 

The comparative trials might include tests 
for iuochronisin, position, and temperature, 
and even be exposed to carriage on a railroad, 
as the final test of all watches is that of ordi- 
nary wear; but it would be impracticable, and 
even unfair in a public test to attempt this 
mode of testing, as they would hardly receive 
uniform treatment ; but a test protracted 
through many weeks might be made ; the 
watches to be exposed to variation of position 
and temperature, without noting the effect 
of each change, each receiving the same 
treatment, and the changes being simul- 
taneous. No account of the smallnesa 
of the rate should be taken, but only the 
uniformity of rate; the amount of rate 
being a mere matter of regulation, and 
having no bearing on the perfection of ad- 
justment. 

"We hope the day is not far distant when 
some one of the American watch companies, 
confident of a higher average of excellence 
in time-keeping than any others, will throw 
down the gauntlet in the form of a challenge 
to all, to enter the tests in a public trial. 
No higher honor than ' the victory in such a 
contest could be desired. Nothing would 
so speedily educate the public up to a taste 
for fine time-keepers. Nothing could so 
stimulate the artisan in the attainment of the 
highest skill in accurate adjusting, for there 
would be a wider demand for such labor, 
and under such a system of competitive 
trials we should see the name of an Ameri- 
can watch becoming the synonym of per- 
fection in time-keeping. 



TAKING IN WORK 



Editoe Hoeological Journal : 

I will tell you how I take in work and de- 
fend myself from the anathemas showered on 
many of the craft. 

In taking in a watch I always request my 
customer to call in at a certain time, and I 
will let him know what his watch needs to 
have done to it, as the universal remedy 



78 



AMERICAN HOROLOOICAL JOURNAL. 



(cleaning) is not always a specific cure for the 
evil of stopping. 

I examine a watch in this way as I take it 
clown : 1st, I see whether the cap jewels are 
well fitted ; try the end shake of the balance 
staff; note the length of the lever; try the 
banking, and examine the fork and roller 
jewel ; then I take out the balance, see 
whether the roller jewel is firmly set, and the 
edge of the roller smooth, examine the piv- 
ots, take off the hair spring, and try the poise 
of the balance. I now find out about the 
locking, slide and drop of the pallets ; after 
that I let down the spring, take out the pal- 
lets and barrel, take out the mainspring, and 
put the barrel back, to see whether all the 
train i3 free ; examine the dep thing and side 
and end-shakes, then take down the train, 
having a small block to put my screws in to 
avoid getting them mixed ; then examine the 
pivots, and try the jewels to see whether they 
are firmly set, and the holes true and perfect. 
If a solid ratchet, see that it is solid and well 
fitted, see how the spring is adapted, and 
tlat the stop-work performs well, and that 
the dial wheels are all right. I try them 
when I first take off the dial. 

Now, for whatever I find to be done, I 
have a regular price, and I charge for it. If 
the customer will not have the watch put in 
order, then, of ccurse, I will not warrant it. 
There are comparatively few but what have 
their watches put in order, and most of those 
who do not will get the best done they can, 
and have it run ; and those who will not 
have anything done I charge, as some M. D.'s 
do, for the examination. In cleaning, I wash 
in warm water and Castile soap, using a fine 
brush, rinse in alcohol, and dry in fine box- 
wood sawdust. Of course all the false plates 
are stripped so that the dust can be removed 
with a fine brush. The train I wash simply 
in alcohol, and dry it off before I put the 
plates in the sawdust, to avoid the danger of 
breaking the pivots. In this way I find out 
all the defects of the watch, and take nothing 
for granted, and I am sure it pa} r s me. I 
test my alcohol by putting in a piece of pol- 
ished steel, and if it does not Change the color 
of it, it answers my purpose. 

J. H. L. 

Concord, N. R. 



HEAT. 



NUMBER THREE. 



LATENT OR SPECIFIC HEAT- — TRANSMISSION OF 
HEAT BY CONDUCTION, BY CONVECTION, BY RA- 
DIATION- FAMILIAR EXAMPLES, ETC. 

When two different bodies are exposed to 
heat, under exactly the same circumstances, 
both will finally reach the same tempera- 
ture ; but one of them will always take a 
longer time in doing so than the other. 
Thus, if two similar and equal vessels, one 
containing mercury, the other water, be 
placed on the same stove, the mercury will 
be raised to 212° before the water boils ; and 
yet the mercury, if of equal bulk with the 
water, is more than 13| times as heavy, and 
might have been expected to have taken 13| 
times as long to reach the same temperature. 
It is obvious, therefore, that all the heat 
which was received by the water has not ap- 
peared in a sensible form, and it is also pos- 
sible that all received by the mercury is not 
sensible. 

"When a solid is converted into a liquid, or 
a liquid into an elastic fluid, the conversion 
is brought about suddenly. The substance 
•in question, before changing its state, con- 
tinues to receive heat, is expanded to a cer- 
tain degree, and has its temperature raised ; 
but if an additional quantity of heat be still 
given to it, the expansion no longer goes on 
in the same manner, and the temperature is 
no longer elevated, but it assumes a new 
form, becoming, according to circumstances, 
either a liquid or a vapor. It was formerly 
supposed that this change did not depend 
upon any peculiar or specific action, but that 
the mere addition of a certain small portion 
of heat was adequate to effect it. Dr. Black, 
a celebrated Scottish Professor of Natural 
Philosophy, and the friend and adviser of 
James "Watt, perceived the insufficiency of 
the opinion usually entertained on the sub- 
ject, and was induced to investigate it with 
great assiduity ; the result of which was to 
establish his celebrated theory of latent heat. 
It would carry us far beyond our prescribed 
limits were we to give an account of the 
experiments which were performed by Dr. 
Black for the purpose of establishing his 
theory, which is generally accepted. The 



AMERICAN HOEOLOGICAL JOURNAL. 



79 



fundamental position of the theory is, " that 
when a solid is converted into a liquid, or 
a liquid into a gas, a much greater quan- 
tity of heat is absorbed by it than is percep- 
tible by the sensation, or the thermometer, 
the effect of which is to unite with the par- 
tides of the body, and thus to alter its form. 
When, to the contrary, the vapor is reduced 
to the state of a liquid, or a liquid to that of 
a solid, heat is disengaged from it without 
the subject in question indicating any diminu- 
q of temperature, either to the sensation, or 
to the thermometer."' Although we cannot 
determine the number of degrees, by any 
thermometer, that will become latent, the 
capacities of bodies to contain it are deter- 
mined by taking one of them as a standard. 
Water is generally used for this purpose, 
and the capacities of most metals for latent 
heat are represented by the following 
figures : 



Bismuth 0.0288 Zir.c 0.0927 

0.0293 Copper 0.0919 

Mercury 0.0290 Nickel 0.1035 

Gold... 0.0298 Iron 1100 

Platinum 0.0314 Cobalt 0.1498 

Tin 0.0514 Sulphur 0.1880 

Silver 0.0557 Water 1.0000 



The capacity of bodies for latent heat may 
be changed by mechanical means. The capa- 
cities of atmospheric air and gases are acted 
upon in this manner. Thus, if we force a 
>n into a syringe, and a piece of timber be 
1 on the piston, it will be set on fire. In- 
flammable mixtures of gases will be exploded 
by the same instrument, and some are said 
to be heated to such a degree as to become 
luminous. Air rushing from a vessel in which 
it has been condensed, will produce a degree 
of cold sufficient not only to convert the 
>r with which the air is mixed into water, 
bat to freeze it into the form of a ball. In 
tmosphere of the earth, those portions 
of it which are nearest the level of the sea 
are compressed by the weight of those above 
them ; they have, therefore, a small capacity 
I itent heat, and their temperature is 
higher than that of the air in higher regions, 
when the pressure being less, the capacity for 
latent heat is greater. We may thus account 
for the great cold experienced on rising in a 
balloon, and on the tops of lofty mountains, 



which, even when the sun is vertical, are 
covered with perpetual snow. 

Heat tends to diffuse itself equally among 
bodies of different temperature ; so strong is 
this tendency, that, unless fresh supplies are 
received, the hottest bodies soon become cool, 
in consequence of parting with their heat to 
surrounding bodies cooler than themselves. 
The cause of this tendency of heat to fly off 
from bodies, or to pass from one to another, 
and thus diffuse itself among them, is attribr 
uted to its possessing an inherent repulsive 
force. The particles of all kinds of pondera- 
ble matter are necessarily attracted to each 
other, unless some counteracting cause pre- 
vents their union. This is equally exempli- 
fied in the attraction which prevails between 
large masses of matter, by which the planets 
are kept in their orbits, called the attraction 
of gravitation, and the attraction which ex- 
ists between the indivisible particles of mat- 
ter, and which influences many of the minute 
operations of nature under the denomination 
of chemical attraction. The repulsive power 
which appears to be an inherent quality of 
heat, may be regarded, in general, as the cause 
of its diffusion among bodies. This equal dis- 
tribution of heat, as it has been called by some 
writers, or the equilibrium of caloric, as has 
been styled by others, has been the subject of 
much observation and experiment, and has 
also given rise to much hypothetical discus- 
sion, which we will not dwell on, but pro- 
ceed to give the generally accepted modes 
by which heat seeks to attain this equilibrium 
of temperature. 

When heat passes from one particle of a 
solid substance to another, it is said to be 
conveyed by conduction. Suppose we pick up 
a piece of metal when the atmosphere sur- 
rounding it is of an ordinary temperature, 
we feel it to be a hard and heavy body, but 
it neither warms nor chills us ; the tempera- 
ture of the metal on the one hand, and our 
sensations on the other, remain unchanged ; 
but if we place one end of the metal to some 
source of heat, the particles of the metal 
nearest to that source become violently agi- 
tated, the swinging atoms strike their neigh- 
bors and expand their distance apart, which 
finally reach our hand and cause the sensation 
known as hea t; but although a familiar ex- 



80 



AMEKICAN HOKOLOGICAL JOUKNAL. 



ample, it must not be understood to be, in all 
cases, a ted of temperature, or the quantity of 
beat that exists in bodies. To prove tbis, ar- 
range tbree bowls, containing water at 32°, 
90°, and 150°, respectively. Dip the two 
hands into the first and third bowls, and 
then at the same instant into the centre 
bowl, containing the water at 90°; to the one 
hand it will feel cold, to the other w T arm. 
When heat is conducted through bodies, it 
does not flash through them instantaneously 
like electricity, but passes successively from 
particle to particle, requiring an appreciable 
time for the passage. It passes through 
bodies with different degrees of rapidity, 
some permitting it to pass through them quite 
rapidly, others only very slowly, and others 
almost entirely intercept its passage. The 
imperfect conducting power of snow, for in- 
stance, arises in a great measure from the 
above cause. When newly fallen, a great 
portion of its bulk consists of the air which 
it contains, as may be readily proved by the 
comparatively small quantity of water it pro- 
duces when melted. Farmers in cold coun- 
tries always lament the absence of snow in 
winter, because, as a consequence, the frost 
penetrates to a great depth, and does much 
injury to the grain sown the previous 
autumn. So great is the protecting power of 
snow that in Siberia it is said that when the 
temperature of the air has been 70° below the 
freezing point, that of the earth under the 
snow has seldom been colder than 32°, verify- 
ing that passage of Scripture which says, 
" God giveth snow like wool." It has also 
been observed, that the heaving up of the 
ground by frost, when protected by snow, is 
much less than when it is uncovered and ex- 
posed. 

Our readers will all be more or less familiar 
with instances where, in the back woods of our 
own country, travellers having been obliged 
to sleep in the open air in the winter, find 
themselves m a glow of heat on waking up in 
the morning, with several inches of snow over 
their water-proof coverings. For the same 
reason, many substances which in the solid 
state are quite good conductors of heat, when 
reduced to powder are very poor conductors. 
Thus, rock crystal is a better conductor than 
bismuth or lead ; but if the crystal be ren- 



dered to powder it becomes a very poor con- 
ductor indeed. Rock salt, when in the solid 
state, allows heat to pass through it with great 
facility, but table salt, in fine powder, ob- 
structs its passage almost entirely. Sawdust 
powerfully compressed allows heat to pass 
through it with the same facility as solid wood 
of the same kind, but when loose and uncon- 
fined it is one of the poorest conductors 
known. Sand is an excellent non-conductor, 
and is often placed beneath the hearths of 
fire-places to guard against accidental fire. 
At the siege of Gibraltar, the red hot balls 
fired by the British, were carried from the 
furnaces to the guns in wooden wheel-bar- 
rows, protected only by a thin covering of 
sand. Near the summit of Mount iEtna, ice 
has been discovered beneath currents of 
lava which had flowed over it when in a liquid 
state, which was only protected from melting 
by a thin layer of volcanic sand. The ice 
gatherers of the same mountain export their 
ice to Malta, and distribute it through Sicily, 
protected by envelopes of coarse straw mat- 
ting ; and ice is conveyed from our own coun- 
try to the most distant parts of the earth 
packed in straw, sawdust, or shavings. Asbes- 
tos, a fibrous mineral substance, is woven into 
an incombustible cloth of such poor conduct- 
ing power, that red hot iron may be handled 
with gloves made of it. Glass is another 
poor conductor of heat ; so poor is it that a 
large red hot molten mass of it may be ladled 
into cold water and the interior remain visibly 
red hot for several hours. 

Heat is conveyed through all liquids and 
gases by a change of place among the parti- 
cles. These particles are transferred in 
whole masses from place to place, and 
convey the heat along with them, and is 
called convection, in contradistinction to the 
process of conduction, just now described. If 
any fluid body be heated from beneath, the 
part which receives the heat first becomes 
specifically lighter than the rest of the liquid ; 
this part will therefore rise to the surface, 
and its place is supplied by the denser part 
of the liquid. A continual current of the 
colder liquid from the surface, and the heated 
liquid from beneath, will thus be formed. 
This current may be rendered sensible as 
follows : Place water in a transparent vessel, 



AMERICAN HOROLOGICAL JOUKNAL. 



81 



and put a little powdered amber into it, which 
has almost the same density as water. On 
applying a lamp to the bottom of the vessel, 
the powdered amber will be seen to circulate 
with the water, and thus exhibit the nature 
and direction of the currents ; while on being 
allowed to cool, the process is reversed. In 
summer, when there is no breeze, we feel 
oppressively warm, because the air does not 
carry off the heat generated within us. Fan- 
ning cools us, because it carries off the air 
heated by contact with our bodies. In this 
case it will be seen that it is carried off by 
con vsction and not by conduction. The exist- 
enca of currents produced by convection is 
seen on a grand scale in nature in the exist- 
ence of trade winds, the Gulf Stream, and 
other ocean currents. The air and the water 
in both cases are not heated from the direct 
rays of the sun, as will be explained in the 
next paragraph. 

A body not in contact with the source of heat 
cannot be heated by conduction or convection, 
and if it receives heat at all it is by a third pro- 
cess, called radiation. All substances radiate 
and absorb heat, but not equally well ; much 
depends on the character of their surfaces. 
TYhen radient heat falls upon bodies it is 
either absorbed (in which case it raises its 
temperature), or it is reflected or turned back 
towards its source, or it is refracted or bent 
out of its original straight course, which oc- 
curs only when it falls at an angle less than 
a right angle, upon some medium which it is 
capable of traversing ; or it is transmitted or 
passed through unchanged when it falls per- 
pendicular upon some medium capable of 
transmitting it, although this rarely takes 
place without more or less absorption. Ra- 
dient heat does not affect the temperature of 
the media through which it passes. A hot 
stove sends forth rays of heat in every direc- 
tion, that pass through the air without heat- 
ing it, but raise the temperature of all bodies 
upon which they strike. In like manner the 
earth is warmed by rays which emanate from 
the sun, and have passed through the air 
without raising its temperature. 

Many other interesting phenomena might 
be mentioned in connection with the radia- 
tion of heat ; but having given our readers a 
condensed dissertation on heat and its modes 



of transmission, which, with a little reflection, 
will enable them to form an intelligent com- 
prehension of some of nature's grandest laws, 
we will, in our next number, proceed with a 
detailed description of the practical effects of 
heat, interesting to young and old, to the 
merchant and to the mechanic. 



EXPLANATION OF ASTRONOMICAL 1EMS 
RELATING TO TIME. 



It is because there is so much confusion in 
the minds of those who have not investigated 
the subject of Astronomy, that we are often 
met with inquiries relating to the difference 
between Apparent and Mean Time, Sidereal 
an I Solar days, etc., and we are led to an 
explanation of these terms ; not that there is 
anything new to be presented, but that, by 
" line upon line," certain fundamental facts 
in Astronomy may be made more familiar, 
and to watchmakers especially, inasmuch as 
the subject is intimately connected with their 
art. For, it will take but little consideration 
to show that while Horology groAvs out of 
the demands of Astronomy, the mutual rela- 
tion becomes so intimate, and the require- 
ments of each so interwoven, that neither can 
fulfil its high purpose without being supple- 
mented by the material aid furnished by the 
other. 

Astronomy discovers and defines certain 
interval of duration, determined by the 
movements of the various members of the 
Solar and Stellar systems ; and according as 
it accepts one or another of these intervals as 
a unit, it measures the length or varying 
durations of the others ; and the interval of 
duration between a particular epoch and an- 
other such is called Time. 

The diurnal motion of the earth on its axis 
furnishes most readily a basis for the meas- 
urement of time, since the exact recurrence of 
each complete revolution constitutes a dis- 
tinct interval, which we are compelled by our 
senses to accept as a unit of measure, because, 
as one side or the other of the earth is pre- 
sented to the sun, we have the alternations of 
light and darkness, which, taken together as 
a whole, make what we call a Day. But the 
length of the day, or a complete revolution 



82 



AMEKICAN HOKOLOGIGAL JOURNAL. 



of the earth on its axis, depends on how we 
measure it ; for, if we do so with reference to 
the sun, we shall find it of a certain length of 
duration, while if noted with reference to the 
stars, it will be quite different. Let us 
illustrate this. Suppose we were situated on 
the edge of a horizontal revolving disc, and 
we notice at one point of our revolution that 
two remote objects, lying beyond the circum- 
ference of the disc, are in range, one of them 
being comparatively near. Imagine a line 
drawn from the centre of the revolving disc 
through the point we occupy. It is evident 
every time we make a complete revolution 
we know it by the coincidence of this line 
w r ith the two objects in range. Now, suppose 
while this disc is revolving about its own cen- 
tre, it also revolves about the nearer of the two 
objects, so that while it makes one revolution 
about its own axis it moves the 3-1^ part of a 
circle around the near object. It will be 
equally clear that after one revolution our 
imaginary line will not point to both the near 
and far objects at the same time ; for when a 
complete revolution of the disc is made with 
reference to the near object, the farther one 
will not be in range, and consequently the 
length of the revolution of the disc will differ 
accordingly as we refer it to the near or dis- 
tant object. 

Now, if we transfer this idea to the Solar 
system, we shall find the same state of 
facts. We shall find the earth moving 
from west to east on its axis ; the distant 
object will be a fixed star, and the compara- 
tively near one the sun. Suppose we set up 
a transit instrument in the plane of the meri- 
dian so we may know exactly when the sun 
or the star, by the revolution of the earth on 
its axis, appears to cross the meridian line. 
When the earth has made a complete revolu- 
tion on its axis, it will also have moved 
forward in its orbit about the sun one day's 
march, and the same effect will appear as in 
the illustration, for the earth will revolve so 
as to get the transit instrument in Hue with 
the star, earlier than with the sun. We may 
remark here that this fact accounts for the 
apparent movement of the sun among the 
fixed stars ; for although they, from no part 
of the earth's oi'bit, present any change in 
their relative positions, by reason of their 



almost infinite distance, yet, as we revolve 
about the sun, that luminary is successively 
brought in range with, and appears to tra- 
verse the space occupied by the constella- 
tions comprising the twelve signs of the 
zodiac. 

Now, if one revolution of the earth on its 
axis constitutes a day, how shall the length of 
the day be determined ; with reference to the 
sun, about which we revolve, or by reference 
to the stars, about which we do not revolve ? 
We cannot use both intervals of time as the 
same basis of measurement. Astronomers, 
therefore, apply different designations to 
these unequal intervals, and call that marked 
by the successive arrival of a certain point in 
the heavens, calleel the first point of Aries, which 
is otherwise known as the intersection of the 
ecliptic and the equator, at the meridian of 
any place, a Sielereal Day, because maele with 
reference to the stars ; and that interval 
caused by the successive arrival of the sun at 
the same merielian a Solar Day, for the 
reason that it is determined by the sun. So 
also, if the diurnal revolution of the earth be 
measured with reference to the moon, it will 
be still different, and such an interval would 
be known as the Lunar Day. Here we have, 
then, three distinct intervals, yet each gener- 
ically termed a day. 

The Day, then, being a natural unit of 
time, may be resolved into any number of 
subelivisions for the purpose of expressing 
smaller intervals of time ; but custom arbi- 
trarily divides it into twenty-four parts, or 
hours, and these again into minutes and 
seconds, as all understand, while the longer 
intervals are expressed in months anel years. 
The subdivisions and multiples of the unit 
day are referable to the kind of day we take 
as the basis of division. Thus, Sidereal Time 
is duration expressed with reference to the 
Sidereal Day. 

It has been found by long continued obser- 
vation that the diurnal motion of the earth 
on its axis is exactly uniform, if measured 
with reference to the fixed stars ; so that the 
interval between the successive transits of 
any fixed star is always precisely the same 
length ; but this interval, or length of the 
Sidereal Day, is proved to be shorter than 
the Solar Day ; and if the latter be taken as 



AMERICAN HOROLOGICAL JOURNAL. 



83 



the unit, or 24 hours, then the former will 
be 23h. 56m. 4s.09 of solar time. 

The Day we most naturally fall iuto the use 
of is that determined by the revolution of the 
earth with respect to the sun, as already ex- 
plained, aud is of that length of time that 
elapses between the successive presentations 
of any point or meridian on the earth to the 
sun ; or, as it appears to our senses, the upper 
transits of the sun across the meridian of any- 
place, and is, therefore, identical with the 
day indicated by a correct noon mark, and 
is properly described as an Apparent Solar 
Day. 

When the sun's centre crosses or transits 
the meridian of any place, that instant is 
called Apparent Xoon, and time reckoned for- 
ward from this instant to the return of the 
sun on the meridian, is called Apparent or 
True Time. And yet it is not the kind of 
time we use in civil affairs, or the ordinary 
customs of society ; for, owing to the want of 
uniformity of the motion of the earth in its 
orbit, and to the inclination of the poles of 
the earth to the plane of its orbit, an in- 
equality arises that causes the successive re- 
turn of the instant of apparent noon with 
considerable irregularity ; and the construc- 
tion and use of a time -piece that would keep 
this irregular, or apparent time, would be 
inconvenient, if not impossible. So astrono- 
mers have devised a kind of time, based on 
solar time, in so far as it has the same num- 
ber of days in the year, and is represented 
by a fictitious or supposed sun having a uni- 
form motion, its time, therefore, showing a 
regular and ecpiable increase, but each day 
of 24 hours being the mean or average of all 
the days in the year, and this is denominated 
Mean Solar Time. The term Day, expressed 
with reference to the movement of the mean 
sun, is called a Mean Solar Day. Mean noon 
is the instant when this suppositious sun is 
on the meridian, apparent noon sometimes 
preceding, and at others, succeeding it. The 
difference between apparent time and mean 
time is called the Equation of Time, and is 
given in tabular form, in any nautical almanac, 
for every day of the year. By its use we may 
convert apparent into mean time, and vice 
verm. If the transit of the sun be ob- 
served with any instrument designed for 



that purpose, but preferably a transit instru- 
ment, the immediate result is the finding the 
instant of apparent noon by the time-piece 
used. By applying the eqration of time to 
this result, according as it is additive or sub- 
ti active, the instant of mean noon is found, 
as shown by the same time-piece; or, in other 
words, its error, whether fast or slow. 

In the method of reckoning, in ordinary 
use, the Civil day begins at midnight, and 
reckons forward 12 hours to noon, and 
thence 12 hours again, to the next midnight. 
The Astronomical day commences at mean 
noon, and 12 hours later than the Civil day 
of the same date, and its hours count from 1 
to 24 continuously, to the succeeding noon. 
Thus, Oct., 1 day 18 h., astronomical time, 
would correspond to Oct., 2 days 6 h., A. M., 
civil time. In nautical usage, the Sea day 
begins at the noon preceding the beginning 
of the Civil day of the same date. 



THE LEVER ESCAPEMENT. 



No portion of the structure of a watch has 
so much labor bestowed upon it — receives so 
much of the thought and skill of the scientific 
and practical horologist — as that portion 
comprising the escapement ; for it is this part 
of the mechanism of the watch that divides 
time into small equal instants, and it cannot 
be too perfectly proportioned, nor too care- 
fully finished. 

There are many varieties of escapements, 
but the most important and the most inter- 
esting is unquestionably the detached lever 
escapement. From its beauty of combination, 
the durability of its structure, and the accu- 
racy of its performance, it has won the favor 
of very nearly all European, and every Ameri- 
can manufacturer, and it is to-day the most 
popular escapement extant. When well car- 
ried out, as to principle and finish, it is sus- 
ceptible of excellent time-keeping qualities 
(in the ordinary acceptation of the term), and 
this, taken in connection with the compara- 
tively small cost for which it can be made, 
places it far above any other escapement. 

The detached lever, as invented by Madge, 
in 1751, although differing somewhat from 
the present manufacture, has nevertheless 



84 



AMERICAN SEROLOGICAL JOURNAL. 



served as a prototype to all escapements on 
the same principle, but differing somewhat in 
form. It is not the object of the present 
article to furnish a complete treatise on the 
lever escapement, as that would occupy more 
space than could be allowed in the Journal, 
and besides, there are already many very ex- 
cellent treatises on the subject, from eminent 
horologists ; but the design is to aid those 
repairers who are seeking to acquire a knowl- 
edge of the principles involved in a good lever 
escapement, the better to fit them to make 
the necessary repairs, when occasion requires. 
From these considerations there will be given 
only the two most common forms of this 
escapement — the English and the Swiss ; the 
difference being principally in the shape of 
the tooth of the escape-wheel — the English 
using ratchet teeth, and the Swiss club teeth. 
This escapement is composed of two dis- 
tinct actions, viz. : that of the wheel and pal- 
let, and that of the lever and roller. From 
this enumeration it will bo seen that the es- 
capement consists of four acting parts — wheel, 
pallet, lever, and roller. The action of the 
wheel and pallet is simply that of rotary con- 
verted into that of vib •atory motion, and is 
effected by means of driving planes on each 
arm of the pallet, acted upon by the wheel, 
and is called the lifting action. There is also 
an action of the wheel and pallet, very neces- 
sary to good performance, called the " c raw," 
Avhich is produced by means of a slight devia- 
tion from the line of the locking-face on each 
arm of the pallet, causing the pallet to be 
drawn in towards the wheel after the latter 
has given its impulse, thus completely detach- 
ing the vibrations of the balance from its 
connection with the other parts of the 
escapement, until the return vibration again 
completes the connection by means of the 
ruby-pin in the roller ; hence its name. 

The action of the roller embodies two func- 
tions — that of impulsion, and that of unlock- 
ing. The pallet, being of one piece with the 
lever (so to speak), is forced by the action of 
the wheel on the p llet, as already described, 
to communicate the impulse derived to the 
balance, by means of the ruby-pin in the 
roller. On the return of the ruby-pin to the 
slot in the lever, it carries it forward just far 
enough to unlock the locking tooth from its 



resting place against the pallet, receiving im- 
mediately after an impulse on that arm. As 
soon as this is accomplished, another tooth 
communicates another impulse to the balance 
by means of the plane on the other arm of 
the pallet, and which action is continuous. 

There is another action, called the safety 
action, which is also very essential to good 
performance in watches, and has for its ob- 
ject the prevention of the lever being thrown 
out of position while the balance is detached 
from the lever, in one of its vibrations ; this 
is effected by means of the roller, which, being 
perfectly round, prevents the lever, when dis- 
turbed by violent external motion, from pass- 
ing the roller by means of a pin or abutment 
on the lever striking against the edge of the 
roller when disturbed, but immediately re- 
turning from that place by the action of the 
" draw," when released by the stoppage of 
external motion. 

There is yet another function of this es- 
capement, also very necessary — that of " bank- 
ing ;" which is nothing more than two pins 
placed at proper distances from each other, 
on each side of the lever. The object of 
these pins is to keep the lever in position, but 
in a contrary manner to that of the " safety 
action." The lever, if not controlled by the 
banking arrangement, would pass out of reach 
of the ruby-pin, acted upon by the " draw " 
already described, on the return vibration of 
the balance. From what has been already said 
of the action and functions involved in a lever 
escapement, it will be seen that it is some- 
what complicated, though not more so than 
many others that are inferior in principle and 
performance ; and besides, in these very 
complications it is- yet simple, that is, easy of 
execution. Now the end we aim to attain is, 
to find the d stance of any given size wheel 
from the pallet, and the pallet's proportion to 
the size of the wheel ; its arms, its driving 
planes, its locking faces, the size of the roller, 
etc., etc. We will treat of the action of the 
wheel and pallet, and of the lever and roller 
separately, considering that of the wheel and 
pallet first. 

To find the exact proportion of the size of 
the pallet to that of the wheel, and the exact 
distance of the wheel from the pallet, first fix 
upon any size wheel, and increase its dimen- 



AMERICAN HOROLOGICAL JOURNAL. 



85 



sions ten or fifteen times, the better to carry 
on the operation, and draw this circle on 
aper; from the centre of this circle (or wheel, 
as we shall hereafter call it) draw a line K, 
as shown in Fie. 1. The number of teeth the 




wueel Has i m cms case 15; mast be known ; 
the pallets are to span 21 teeth of the wheel ; 
this will then farm an arc of 60°; as 3G0°, the 
whole circumference of the wheel, divided by 
15, the number of wheel teeth, equals 21°, the 
distance from one tooth to another, this 
quotient multiplied by 1\, the number of teeth 
the pallet is to span, will give 24° X 2^ = 60° ; 
which are laid out, with the aid of a pro- 
tractor, to 30° on each side of the line K, and 
marked a, from the centre of wheel C. Next 
proceed to draw lines t. These lines 
must be drawn so as to touch the periphery 
of the wheel, and form a right angle with the 
line a and the point where the lines t cross 
each other will indicate the centre of motion 
of pallet M. 

Next proceed to determine the strength of 
the arms the pallet is to have, which must be 
equal to one half the space from one tooth to 
the other, which is 12° ; but from this we 
must take 3° for the requisite fall of the tooth 
after giving the impulse, which gives us 9° 
for the strength of the pallet arms, which we 
mark on the right side of the line a, from the 
centre of wheel C, and draw into curves from 
the centre of pallet M, and marked s s, as 
shown in the figure, thus making the locking 
faces equidistant. 



Now proceed to determine the lifting and 
locking faces of the pallets. In this case we 
have taken 10° for the lifting plane, and 1£° 
for the locking face ; the whole movement of 
the pallet will then be 11|°, which we draw 
from centre of pallet M, and equidistant on 
each side of the lines t, and marked d, b; 
but 11|° being the whole movement of the 
pallet, and as we already know that 10° is the 
lifting plane, and 1\° the locking plane, so, to 
distinguish the lifting from the locking, we 
draw a line, c, from the centre of pallet, M, 
1|° distant from and below the line b. To 
find the face of the pallet arms, draw a line 
from the point where the line c crosses the 
curve- s, to the point where the line d crosses 
the curve s. 

Next proceed to determine the angle to be 
given the locking faces, so as to create the 
" draw." From the point e draw a line, r ? 
on the right side of the line a, at an angle of 
15° on the arm where the tooth commences 
its action, and 12° on the arm where the 
tooth ends its action ; these will give the 
proper locking faces, with the tendency of 
the pallets to be drawn towards the wheel 
when the tooth is at rest. We finally deter- 
mine the inclination of working faces of the 
teeth from a straight line to the centre of 
wheel, C, which is generally from 28° to 30° ; 
but in this case it is 28°, which is drawn from 
the point of any tooth, as shown in the 
figure. 

The escapement just analyzed is the Eng- 
lish method of carrying out the lever escape- 
ment, and the escape wheel has ratchet teeth. 
We will now consider the lever escapement 
as adopted by the Swiss — having club teeth, 
and where the driving planes are partly on 
the teeth of the wheel, and partly on the arms 
of the pallet. To plan this escapement, fix 
upon the size of the wheel and the number of 
teeth it is to have, and then increase the di- 
mensions of the wheel ten or fifteen times, 
and draw the circle or wheel on paper, as 
shown in Fig. 2 ; then draw line K, from the 
centre of wheel, C ; as- we purpose to have 
the pallets span 2| teeth, and the number of 
wheel teeth to be 15, we will then have 
360°, the circumference of the wheel ; divid- 
ed by 15, the number of wheel teeth, gives 
U3 21° for the span from one tooth to the 



86 



AMERICAN HOROLOGICAL JOURNAL. 



other; this multiplied by 2 \, the number of 
teeth the pallet is to span, gives 24° X 2| = 
60°, which are laid out, by the aid of the pro- 
tractor, on each side of the line K to 30°, and 
marked a ; next draw the lines t, so that they 
touch the periphery of the wheel and form a 
right angle with the line a. Where the lines 1 1 
cross each other is the centre of motion of 




the pallet, marked M. "We must next proceed 
to determine the strength of the pallet arms 
and the wheel teeth, thus : 24° being the 
space from one tooth tu another, we take a 
sixth part of this (4°) for the strength of the 
wheel teeth, anil will then have 20° left ; from 
this take one half (10°) for the strength of 
the pallet arms, deducting 2° for the requi- 
site fall of the tooth after giving the 
impulse, which leaves 8° for the strength 
of the pallet arms ; these 8° we now mark on 
the right side of the lines a, from the centre 
of wheel, C, and then draw into curves, s, s, 
from the centre of pallet, M. We next give 
to the wheel teeth their proper inclination or 
driving planes, which, in this case, should be 
4°, and which are drawn below the line t 
from the centre of pallets M, and marked c, 
from this point where the iines a, and c, 
cross each other, we draw a circle from the 
centre of wheel, C, and marked q, as shown 
in the diagram, which determines the proper 
place for the fore end of the wheel teeth. 

The next thing to determine is, the lifting 
and locking faces. The lifting 1 face in this 



case is proposed to be 6°, and the locking 1|° 
for each pallet arm, which we proceed to 
draw thus : From the centre of pallet, M, 
draw the line d, below the line c, 6° distant 
from the line t, which gives the lifting angle 
proposed, and from above the line t, 1|° dis- 
tant, draw from the centre of pallet, M, the 
line b, which gives the locking-face as pro- 
posed. To find the face of the pallet arms, 
draw a line g, from the point where the line 
t crosses the curve s to the point where the 
line d crosses the curve s, the driving planes 
of the pallet arms. Then proceed to deter- 
mine the angle to be given the locking faces 
in order to create the requisite " draw ; " 
this, as in the preceding case, has 15° 
on the arm where the tooth commences 
its action, and 12° on the arm where the 
tooth ends its action, drawn from the point 
e, and marked r. 

To give the teeth their proper shape, we 
give for the breadth 4°, before determined, 
marked from the wheel centre, C, by reason 
of which are found the driving planes of the 
wheel teeth ; that is, a line drawn from the 
fore end of the tooth in the circle q, to the 
periphery of the wheel in the limit of 4°, as 
shown in the diagram. We finally determine the 
angle of the working faces of the teeth, which, 
in this case, should be 28°, drawn from the fore 
end of a tooth. When it is required to re- 
duce the proportion found of pallet to wheel, 
arms, locking face, lifting plane, etc., etc., 
each part will only have to be diminished as 
many times as the original size of the wheel 
was increased. 

By the method above given a repairer will 
be enabled to test the soundness in principle 
of the action of any wheel or pallet of which 
he may be doubtful. The description has 
been purposely minute in order that those 
having never planned an escapement will be 
better able to understand it and apply it. In 
the next number of the Horological Journal 
will be considered the action of the lever and 
roller. 

N. Y., Sept., 1870. Chas. Spieo. 

[figg 05 We are requested -by Mr. Spiro to 
state that it will not be possible for him to 
take any more orders, as he expects to leave 
for San Francisco in about two months, from 
which place he will continue to correspond 
with the Journal.] 



AMERICAN HOROLOGICAL JOURNAL. 



87 



DIALING. 



NUMBER FOUR. 



A North Erect Dial (Fig. 12) is constructed 




the quadrant S D into six equal parts, lay the 
ruler at C, and to those parts in the circle, 
and it will cut the line A B in those points 




on a wall, or plane, facing the true north 
point. This dial is useless from September 
22d to March 21st, while the sun is in the six 
southern signs (to those who inhabit the 
northern hemisphere), because it can only 
show the time from the sun's rising until six 
in the morning, and in the evening from six 
till sunset ; consequently we shall not give its 
construction particularly, but only say it is 
exactly the same as the South Erect dial, only 
the stile points upward, and the line VI. VI. 
is drawn at the bottom instead of the top oi 
the dial-plane. 

A Direct East Dial is drawn on a plane 
parallel to the meridian. Consequently the 
hour lines are parallel to the earth's axis, and 
to each other. The sun comes on it at its 
rising and continues on it until noon. The 
VI. hour line is the substilar line, and the stile 
may be a thin plate of metal or an iron rod. 
At about two-thirds the distance from the 
lower edge of the dial-plane draw the hori- 
zontal line A C H. (Fig. 13.) At some 
convenient distance, as at C, draw a circle 
with a chord of 60° ; then take the chord of the 
latitude of the place and set from H to P, 
and draw the G o'clock hour line PGS, which 
is the substilar line, to which, at right angles, 
draw the equinoctial, C D. Next draw the 
line A SB, parallel to the equinoctial ; divide 



through which the hour line must pass ; 
through those points draw them parallel to 
the 6 o'clock line and you will have the pro- 
per hour lines. The smaller subdivisions of 
course you can construct by subdivision, as in 
the other dials. The stile fix on the 6 o'clock 
line, at right angles to the plane of the dial ; 
its height equal to C D. 

An Erect-Direct Wert Dial is constructed 
exactly like the east dial, except that you 
draw your circle to the right, on the horizon- 
tal line, instead of at the left, as in the East 
dial ; cons quently the hour lines will be ele- 
vated to the left instead of the right, as 
shown in Fig'. 14. 




In drawing dials for planes' not direct — that 
is, declining to the east or west — it becomes 
necessary to ascertain the amount of declina- 
tion ; and this can be determined by a very 



AMERICAN HOROLOGICAL JOURNAL. 



simple instrument, which you can construct 
yourself. Get a good-seasoned bit of board, 
exactly square ; cover one side with paper nicely 
pasted on, and draw on it, from the centre, two, 
three, or more, concentric circles. Through 
the centre at I, let there be a hole to receive a 
straight wire to screw (or slide) up or down 
at pleasure,' and to constantly stand at right 
angles to the plane of the board itself ; draw 
two diameters exactly perpendicular to the 
edge of the board, and mark them N. S. E. 
W. ; when the north edge of the board is 
placed against an exact south wall, the line 
N. S. becomes the 12 o'clock line ; or what- 
ever the wall declines, that line is perpendicu- 
lar to the wall itself. 

To take the Declination. — In the forenoon, 
when the sun is shining, apply the edge of 
the instrument, A B, to the wall ; set it per- 
fectly horizontal by your quadrant ; screw up 
the perpedicuiar pin in the centre till the top 
of its shadow touch anj r one of the circles, say 
at the point F (Fig. 15) ; let things now rest 




until afternoon, and observe when the top of 
the shadow is on the same circle, and there 
make a dot at G. Take down the instrument, 
and with your compasses subdivide the arc 
F H at G, and draw a line through the cen- 
tre to K, and you will have the true 12 
o'clock line. The angle N I G is the degree 
of declination of the wall, which amount you 
can find by applying the d: stance N Gto your 
line of chords. When the line G K falls on 
the east side of N S, the declination is east ; 
and when on the west side, it is west. 

Erect Declining Dials. — As we have before 
mentioned, those upright dial planes, which 
decline from the north or south points to- 
ward the east or the west, are called declining 
dials, and the first thing to be ascertained 



before attempting their construction, is the 
amount of the declination of the dial plane. 
Suppose you wish to make a dial on a 
south erect plane, whose declination is 21° 10' 
West, for the lat. of 52° 25' N. Draw the 
horizontal line A B (Fig. 16) ; from C, let fall 




the perpendicular, C 12, for the 12 o'clock 
hour line, and from the line of chords take 
60°, and with one foot of the compass in C, 
draw the semicircle ADB; take the com- 
plement of the lat. (36° 35') from the line of 
chords, and set it from D to E, and draw E 
F parallel to A B ; this done, take in your 
compasses the plane's declination (21° 10') 
from the line of chords, and set it from D to 
G ; take E F in your compasses, and set it 
from C to H, and draw H I parallel to A B ; 
take H I and set from F to L, and draw C 
L M. Now, D M, measured on your line of 
chords, is 15° 21' — the distance of the sub- 
stilar line from the 12 o'clock line. 

For the Stile's Height. — From the point H 
draw the line H K parallel to C D; then 
take H K in your compasses, and set from L 
to N, and draw C N for the top of the stile. 

For the Hour Lines. — In any convenient 
place in the substilar line (depending on the 
size of the dial), as at M, draw the hue R S 
at right angles to the substilar line C M ; set 
one foot of the compass in M, and take the 
nearest distance to the stile's height ; one 
foot resting in M, turn the other to Q, in the 
substilar line ; upon Q as a centre, with the 
distance Q M, draw the dotted circle which 
represents the equinoctial; lay a ruler from the 
centre at Q, to the point where the lines C 12 



AMERICAN HOROLOGICAL JOURNAL. 



83 



21° 10' 



and R S intersect (D), and where the ruler 
cuts the dotted circle (at O); there begin and 
divide it into 21 equal parts, which mark 
with little dots ; lay the ruler to the centre, 
Q. and to every one of the equal divisions in 
the equinoctial, and where the ruler cuts the 
line R S, there make a mark ; then by draw- 
ing lines from the centre of the dial at C, 
through each of those marks in the line R S, 
you have drawn the correct hour lines, which 
you may then number in the margin of the 
dial. The stile must hang directly over the 
substilar line, and the top be so placed, by 
your quadrant, that the thread will cut the 
exact latitude of your place on the Hmb of the 
quadrant. 

In constructing this dial you have, in fact, 
drawn four dials, viz. : 
South, declining East 
West 
North " East 

West 
You will observe that it is not the stile that 
changes its position but the plane itself, for 
the style, answering to the latitude of the 
place, remains constantly the same in all 
declinations ; so that if you conceive a plane 
declining (as in the example) 21° 10' west- 
ward, the substilar line falls between the hours 
of one and two in the afternoon. Suppose 
the same plane to be moved to the eastward 
21° 10', the substilar line will then fall among 
the morning hours; audit always follows, that 
if the plane declines eastward, the substilar line 
will fall among the morning hours, and if to 
the west, among the evening hours ; conse- 
quently the name of the hour lines must de- 
pend on the direction of the declination, and 
by reversing the dial (turning it upside down) 
you have a north declining dial for whatever 
degree of declination it is constructed — which 
in the example is 21° 10'. 

Declining-Reclining Dial. — Such planes as 
directly face the North or South points, but 
which recline, that is, lean from you as you 
face them, like the roof of a house, are 
called North or South direct planes, reclin- 
ing so many degrees as they deviate from a 
perpendicular. You can find the degree of 
reclination by applying the edge of your 
quadrant to the plane, and the thread will 
cut the limb in the number of degrees which 



the plane reclines. There may be six varie- 
ties, three South and three North, either of 
which may be reduced to new latitudes ; then 
they become horizontal planes for all pur- 
poses of construction, and consequently the 
hour lines can be drawn on them as pre- 
viously directed. 

Direct South Recliners. — Suppose a direct 
South plane in the latitude of 52° 12' N., 
which reclines from the zenith 26° ; in what 
latitude will that be a horizontal plane ? 
Now, because the reclination is less than the 
complement of the lat. (37° 48'), subtract 
the plane's reclination (28°) from the com- 
plement of the latitude, and the remiinder 
(11° 48') is the new latitude. 

Operation : 

90° 
Latitude of place - - - 52 12' 



Complement of lat. - - 37 48 
Reclination of plane - - 28 

New latitude ----- 11° 18' 
Therefore a horizontal dial, drawn for a lat. 
of 11° 48', will be the proper construction of 
a dial for the lat. 52° 12' N, with a recli- 
nation of 26°. If the reclination of the plane 
equals the complement of the lat., then the 
new lat. is nothing ; that b , the pole has no 
elevation above such a plane, and the hour 
lines upon it will ail be parallel to the plane 
itself ; in fact, it becomes a polar .dial. If 
the reclination exceed the complement of 
the lat., the complement must be subtracted 
from the reclination, which will give you the 
lat. for the construction of a dial for that lo- 
cality. 

Example : A plane whose reclination is 
56° in the lat. 52° 42'. N. 

Operation : 

Reclination ----- 5G° 
Comp. of lat. ----- 37 18' 



Correct lat. for c :nstruction - 18° 12' 
In finding the new lat. for north recliners, 
if the reclination be less than the comple- 
ment of lat., add them' together. Such dials 
(north) are so seldom desired, owing to the 
very short time the sun is upon them, that 
more extended rules for drawing them are 
not deemed necessary, nor shall we devote 
valuable space to directions as to such un- 



90 



AMERICAN HOROLOGICAL JOURNAL. 



usual positions as Erst and West reclining 
dials. 

Reflecting Dials — May be convenient in many 
situations, and are made by placing a small 
horizontal mirror so as to reflect the sun's 
rays to the ceiling. It is a very neat arrange- 
ment for a watchmaker who has a south win- 
dow, for in this manner he can construct a 
very large dial on his ceiling over head, quite 
out of the way, and always convenient to ob- 
servation. The little mirror, if of glass, should 
be as thin as it is possible to obtain, for the 
reason that there are two reflecting surfaces 
to every glass mirror, which each form an in- 
dependent image of the sun ; and as the two 
reflective surfaces are not in the same plane, 
the images will not coincide on the wall, but 
overlap each other a little, producing an in- 
distinct outline prejudicial to exact observa- 
tion ; and the more the reflecting surfaces 
differ from the same plane, the more will the 
produced images overlap. A metallic surface 
forms the best mirror ; a bit of polished steel 
is excellent, if the surface is protected from 
oxidation, as its reflected image of the sun 
forms a clear, distinct outline. 

Method of Construction. — Place your mirror, 
which need be no larger than a silver five- 
cent piece, in a truly horizontal position ; this 
you can perhaps most conveniently do by ob- 
serving in it the reflected image of the ad- 
jacent corners of the room, or of the window 
casing or sash bars, or any object within view 
which has perpendicular lines sufficiently well 
defined. If your mirror deviates from hori- 
zontal, these reflected perpendiculars will not 
be straight lines, but bent at the surface of 
the mirror ; but by repeated observations, in 
various directions, and corresponding changes 
of level in the mirror, you may get it suffi- 
ciently accurate for the purpose. 

Having fixed the mirror, you must draw a 
meridian line, which you can do by suspend- 
ing a plumb line over the centre of the mir- 
ror, which line will cast a shadow on the floor 
at meridian, and which will be the 12 o'clock 
hour line ; or you can construct such a line 
by the process heretofore described. This 
being done, the meridian line on the floor 
must be transferred to the ceiling, which may 
be accomplished by the help of two plumb 
lines — one over the mirror, the other over the 



other end of the 12 o'clock line, as at A, Fig. 
17, by which means you will have two points 




on the ceiling over the meridian line on the 
floor. Between these two points stretch a 
line, charged with lamp-black and oil, and 
snap it (after the manner of a chalk line), and 
you have permanently the 12 o'clock hour 
line A C ; make the angle DRP equal to the 
complement of the latitude of the place (say 
36° 30'), which you must do by the aid of a 
string held, one end at the mirror R, the 
other at the ceiling, represented by B R, and 
apply the edge of your quadrant till you find 
the thread of it cuts the limb at 36° 30'; 
through that point of the 12 o'clock line (at 
B) the equinoctial line must pass, which draw 
at right angles to A D, which is a straight 
line, as you see in the figure. 

To draw the Hour Lines. — With any con- 
venient opening of the compass, draw the 
semi-circle R L M, and divide it into 12 equal 
parts ; but because the centre of the dial does 
not fall in the room, but out of it in the open 
air at O, before the hour lines can be dra^n 
you must ascertain the angle that each hour 
line makes with the 12 o'clock line, and their 
complements are the angles that they make 
with the equinoctial. This can be done by 
calculation ; but as these directions were to 
be mechanical, you must proceed to draw a 
horizontal dial for the latitude of the place 
you are in, as shown at Fig. 17, and with 
your compasses and line of chords measure 
the angles that the hour lines make with the 



AMERICAN HOEOLOGICAL JOURNAL. 



91 



meridian, and set them down in a table, as 
follows. Suppose the lat. be 53° 30' : 



Hours. 


Angle 


with Mer. 


Angle with 
Equinoctial. 








O 1 


12. 











1. 11. 


12 


10 


77 50 


2. 10. 


24 


54 


65 06 


3. 9. 


38 


47 


51 13 


4. 8. 


54 


19 


35 41 


O. 1, 


71 


34 


18 26 


6. 












Lay your quadrant to the meridian line and 
make angles upon the ceiling equal to those 
in the second column of the table ; or you 
may lay it to the equinoctial line on the ceil- 
ing and make the angles for every hour equal 
to those in the third column of the table ; and 
by the use of your blackened string, draw the 
hour lines permanently upon the wall ; or 
they may be drawn another way, if you think 
this too tedious. "When you have drawn the 
horizontal dial for your latitude, place the 
centre of it at the centre of the mirror, and 
fix a thread at the centre of the dial ; lay the 
thread straight over every hour of your hori- 
zontal dial, fasten it at the other side of the 
room, and so transfer them to the ceiling as 
you did the meridian line, by the aid of plumb 
lines. 

We shall give you one more construction 
which will be space enough devoted to an 
obsolete art, and will close what we have to 
say at prevent on the subject of dialing. 

Globe Dial. — This dial, drawn upon a solid 
or hollow sphere, shows the hour of the day 
without a stile or gnomon. Procure a sphere, 
either wood, stone, or metal, which must be 
fixed upon a pedestal of any kind you choose ; 
then proceed to draw upon it the circles of 
the sphere, which you can do by the help of 
a semicircle which just fits the sphere. A B 
being the horizon, Z N the prime vertical, 
draw P S, the earth's axis to your latitude ; 
make Z E equal to P B, and B G equal to 
A E, and draw E Gr for the equinoctial; which 
divide into 24 equal parts, and through those 
divisions draw the meridians or hour circles, 
all meeting at the poles. At 23° 29' from the 
poles draw the polar circles ; and the same 
distance north and south of the equinoctial 
draw the tropics Capricorn and Cancer, and 
from 53 to V5 draw the ecliptic; on which you 



can, if you choose, place the signs of the Zodiac, 
beginning at the intersection of the equinoc- 
tial and ecliptic, and measure off 30° for Aries, 
and 30° more for Taurus, and so on for each 
successive sim 30°. 




The hours must be numbered in the equi- 
noctial, placing 12 in the east and west points 
of the horizon, and 6 in the meridian; be- 
cause one-half the globe is illuminated, and 
the edge of illumination shows the hour in 
two opposite places. On it, if you choose, 
can be drawn the outline of the principal 
countries and cities, according to their true 
longitude, shoAving what places on the globe 
are enlightened and what in darkness; where 
the sun is rising and where setting ; and in 
fact all the various and interesting problems 
of the globe. Wires also inserted at the north 
and south poles will show the hours — north 
in summer — south in winter. 

"We see in the Revue Chronometrique, pub- 
lished by M. Saunier, Paris, the description 
of a new equatorial dial so adapted in the 
manner of putting it up (ball and socket 
joint) as to popularize it for more general 
use. Of course, being equatorial, it is drawn 
on both sides, upper and lower, with the 
equation table for mean time fixed on the 
upper dial for the summer months, and on 
the lower dial for the winter months. It 
is easily adjusted to the latitude by direct- 
ing the gnomon to the polar star, and to the 
meridian by setting it from any correct time- 
piece. 



92 



AMERICAN HOKOLOGICAL JOURNAL. 



PATIENCE. 

Patience is an element of character most 
admirably fitted to adorn the watchmaker as 
well as the Christian gentleman. Few occu- 
pations have an equal amount of petty annoy- 
ances in their prosecution, and querulous 
operatives are frequently heard wishing that 
the famous historic personage who afforded so 
shining an example of its excellence in his own 
personal sufferings had been a member of their 
profession, that they might have seen whether 
he would not " have fell from grace " under its 
manifold temptations. We once, in our ver- 
dancy, ventured to say that were Job a watch- 
maker, we were sure the lustre of his fame 
would have been tarnished by the use of some 
very improper expletives. No doubt he was 
very grievously tormented, and that he de- 
serves the full measure of praise bestowed on 
him ; nevertheless, we are not disposed to 
permit him to enjoy a monopoly of the virtue 
of patience; others besides him have suffered 
and borne, but have not been equally fortu- 
nate in securing so exquisite a poetical fancy 
to depict their trials and triumphs. This 
beautiful virtue assumes so many and diver- 
sified forms — each rendered distinctive only 
by combination with other personal charac- 
terists — as to defy classification ; and whether 
we shall succeed in bringing out clearly any 
special attribute peculiarly adapted to our 
calling remains to be seen. 

It certainly is something different from that 
form manifested under affliction, which weeps, 
yet kisses the hand that smites; or that meek- 
ly prays for the bitter cup to pass when dis- 
ease lays its burning palm on the brow, and 
sets the life blood rushing through the veins 
at fearful speed ; or that, when death robs 
us of our heart's treasure, and plucks out the 
very eye of our existence, clasps its hands, 
and turns its tearful eyes to heaven, saying, 
"Father, not my will, but Thine be done;" 
neither is it that physical fortitude which en- 
dures the knife and saw without a groan, or 
permits the bigot's fire to consume the body 
by hell's own torture, without a sigh, or the 
movement of a muscle; nor is it the bodily 
and mental endurance which uncomplainingly 
labors day and night, in heat or cold, to earn 
the pittance which links body and soul toge- 



ther ; nor yet the calm which settles on the 
soul, tearless and awful, when calamity, al- 
most too great for endurance, overtakes and 
crushes. 

All these, and more, are forms of patience 
derived from Christian submission, or consti- 
tutional fortitude, and are phases quite dif- 
ferent from what we have in contemplation. 
The quality we speak of is shown in the calm 
unruffled endurance of little provocations — 
diminutive irritations — which oftener arise 
from our own neglect or stupidity, and which 
we cannot blame upon others — than from 
pure accident ; it is a patience which comes 
from education, and is often exhibited in a 
marked degree in affairs pertaining to one's 
calling, without in the least influencing the 
general character of the person. We have 
known workmen search for hours without a 
murmur for a minute article lost, and yet 
bristle up, "like the fretful porcupine," at 
the slightest word of provocation. 

We do not expect in the wide-awake ener- 
getic man no sign of anger ; such a person 
would be more than human ; to seek to extin- 
guish it entirely is but the bravery of a stoic; 
but the proper control of it, is about our defi- 
nition ; limiting it in degree and duration, 
constitutes patience. The constant endeavor 
to do this is a part of the necessary educa- 
tion of the practical workman ; and we have 
found no better way to do this than to medi- 
tate on the subject after the provocation has 
ceased. Seneca says : " Anger is like rain, 
which breaks itself on what it falls." Men 
must not become wasps and sting themselves. 
Anger, when uncontrolled, is the unmistakable 
evidence and accompaniment of weakness ; 
consequently, is pardonable in children, dis- 
eased, or old and infirm persons ; but a strong 
man in its grasp is from that moment in the 
power of his adversary, and becomes a fit 
subject for ridicule. Whosoever cannot pos- 
sess his soul in patience is at the mercy of 
circumstances. What can be more ridicu- 
lous than a man, perhaps " grave and rever- 
end," standing on tip-toe, on the top of a 
high stool, stretching himself to his utmost 
limit to reach a top shelf ; suddenly the stool 
" flips" from under him, and he is sprawling 
on the floor ; instantly angry, dispossessed of 
his patient soul, he kicks the harmless stool 



AMERICAN HOROLOGICAL JOURNAL. 



93 



to the further end of the room, and in so 
doing breaks his leg ; in spite of his agony 
who can help smiling at his folly ? 

So is he a fit subject for mirth, who, in a 
sudden gust of wind, becomes the servant in- 
stead of the master of — his hat, and follows 
it as fast as his legs can carry him. No 
" laugh comes in" when the owner patiently 
waits for the hat to quit its frolic, and lets 
" patience have her perfect work;" the man 
then continues master of the hat. 

Our daily lesson in education should be 
quiet endurance of all momentary irritations ; 
that will always give the man complete mas- 
tery of the situation, save him from further 
injury to himself, and from becoming ridicu- 
lous in the eyes of his fellows. 



GARLIC JUICE VS. MAGNETISM. 



We have always deprecated the publication 
of receipts, processes, or methods that were 
not well authenticated, and been thoroughly 
proved. Earlier in life we have been led 
many a long chase in pursuit of a result said 
to follow when certain things were done so 
and so. Now we are a little cautious of wast- 
ing time (mostly gone) and money, upon 
experiments obviously contrary to our experi- 
ence with the law3 of Nature ; or even ven- 
turing much on statements of processes that 
did not seem to show any analogy between 
the means and the end. One of these experi- 
ments we have just tried, and are almost 
ashamed to own it. A long time ago we read 
in a little pamphlet published in St. Louis 
for the use and instruction of watchmakers, 
that garlic juice would extract magnetism 
from any piece of steel so charged. Not being 
able to see any possible relation between the 
means and the result, we concluded it could 
not be true, and didn't try it; but recently we 
have received a communication from a valued 
correspondent on the subject, wherein he 
describes several experiments going to show 
that onion will do the thing. We were still 
unbelieving, thinking there must be some 
error in his observations — some condition 
which ho had overlooked; so we experimented, 
following his directions as near as possible, 
and the result verified our expectations. We 



took a square, pivot file which was strongly 
magnetic, taking careful note of the weight it 
would sustain^ and placed it between the two 
halves of an onion, fitting it in nicely, and 
bound them together and watched for the 
result which was stated would follow in a 
few minutes. In ten minutes, no result ; in 
twelve, none ; none in an hour, and in 24 hours 
the magnet was as strong as ever. Think- 
ing that the original formula (garlic) might 
succeed, we tried that ; and our tears bore 
witness to the same signal failure. Wherein 
our test was erroneous we cannot see ; we 
took the utmost pains, consequently we must 
be pardoned for remaining incredulous till 
we have further proof. 



THE NEW YOBK WATCH COMPANY. 



About the first of May last, Mr. Richard 
Oliver, of No. 11 John street, who had enjoyed 
a reputation for dealing in fine watches, be- 
coming satisfied that the productions of the 
above Company would do credit to his repu- 
tation, associated with himself Mr. Peter 
Balen, Jr., and made arrangements for the 
entire production of the factory. A few weeks 
afterward the building, together with the 
heavy machinery, was destroyed by fire. This 
calamity occurring during working hours, 
while all the employees were on duty, the 
greater portion of the tools and small ma- 
chinery was saved, together with the material 
in different stages of completion, which en- 
abled them to provide temporary accommo- 
dations and go to work again with very little 
delay ; and now, we are happy to say, they 
have so perfected their arrangements as to 
be able to meet all demands made upon them 
for their watches. 

Availing themselves of all the past experi- 
ence of the other factories, they were enabled, 
at the start, to provide themselves with the 
best machinery that could be made — their 
machine shop, in particular, being without a 
rival in quality. The style of their watches, 
so far as already produced, is f plate, and we 
consider it in every respect much more dear- 
able than the old full plate movement, though 
they are making arrangements to produce, in 
a short time, that style of watch, thereby 



94 



AMERICAN HOROLOGICAL JOURNAL 



bringing themselves in direct competition, 
both in price and quality, "with the other com- 
panies. The design of the watch is plain and 
neat, and the work is simple, sound and well 
finished ; and, having a quick vibration, and 
a tempered spring, is capable of a very accur- 
ate adjustment. We have carried one for 
several weeks, taken at random out of the 
stock (and 2d quality), for the purpose of 
testing their performance, and can say that that 
or,e has performed remarkably well, and see 
no reason why the others should not do as 
well. 

c 

STAKING TOOLS. 



Editor Hoeological, Journal : 

Noticing a description of a new " staking 
in a late number of your paper, I am 



tool' 



induced to write you about one which I have 
had in use for the past three years, which Mr. 
Farjeon, of Nassau street, sells. This tool 
costs but $7, which brings it within reach of 
all. It is made of the best cast-iron, very 
much on the st}le of the old Swiss uprighting 
tool, having a base of about two inches, and 
runs up, on a taper, about one and one-half 
inches, where it has a "face" of about one 
and one-fourth inches across. From the side 
of this face an arm runs up, in the form of 
nearly a half circle, and ends with a piece 
extending upward about two inches, directly 
over the edge of the "face" of the tool. On 
this "face" is a hard, polished, circular steel 
plate, which revolves on a turned steel pin, 
passing down through its centre. Through 
this pin is drilled a hole, nearly at the bot- 
tom, and through the back of the tool runs a 
screw with a taper p->itit, which, being forced 
into the hole in the pin, draws it down and 
holds the steel plate firmly in its place. This 
steel plate is full of graduated holes, and any 
one of these holes is brought directly under 
the punch by revolving the plate and putting 
the "pointed centre" down into the hole ; then 
turn up the back screw and the plate is fast. 
This tool has with it twenty punches, both 
round and flat faced, with holes in them, 
ranging from the very finest Swiss pinion up 
to largest centre pinion. Also there are two 
solid punches for riveting bushes — one round 



and one flat faced ; also ono for stretching 
wheels, and one for pushing down a roller 
perfectly true. There are also four " stubs" 




to put in the largest holes, to rivet bushes on, 
alter the "end shake," and one to rivet a 
balance with the rim down. This tool is one 
every workman needs, and its price being so 
low should induce every good workman to 
order one. 

The accompanying drawing will give a good 
general idea of the appearance of the tool. 

E. A. Sweet. 

New Yoke, Sept. 26, 1870. 



ANSWERS TO CORRESPONDENTS. 

T. G., Wilmington, Del— Asks " Why do the 
American Watch Co. send their watches into 
market without having the forks and levers 
poised? In the three-quarter plate Apple- 
ton & Tracy watch, for instance, where every- 
thing else in the escapement is beautifully 
finished, and the geometrical proportions 
correct, why is this important condition of 
the lever wanting ? Is the necessity of it 
ignored, or is it omitted through neglect? 
Will one of the Company please inform us ? 
The fact of having to correct such discrepan- 
cies in watches as highly recommended as the 
one in question, and .when in the finished 
state, is excessively annoying." 

We cannot answer for the Company, but 



AMERICAN HOEOLOGICAL JOURNAL. 



95 



we can say that a watch which makes pre- 
tence to such accuracy as to be adjusted to 
temperature and position, should also be as 
near perfect in the poise of the pallets as may 
be ; for there is a possibility of error in 
change of position where such imperfection 
exists. Every mechanic and mathematician 
is aware how rapidly very small but constant 
increments of time or space accumulate ; 
the error may be only the infinitesimal part 
of a vibration of the balance, and it may be 
much more than that in those watches in 
which the lever is oblique, or at right angles 
to a vertical line from the pendant ; yet, in an 
hour the quantity of these minute errors 
amounts to 16,000 or 18,000, and in a day 
is increased to the number of 132,000, a quan- 
tity which certainly begins to be appreciable. 

Of course there is another side to this ques- 
tion ; some, who are high authority, asserting 
that unless the want of poise is sufficient, by 
violent agitation, to unlock the pallets and 
bring the guard pin in contact with the 
roller, that the minute additions or diminu- 
tions to the momentum of the balance by the 
lever being slightly out of poise, counterbal- 
ance each other perfectly. 

"We are heartily glad of one thing, how- 
ever, which is, that the trade are becoming 
critical, and are reasoning, philosophizing, 
and educating themselves to a higher stand- 
ard of excellence ; these are indications in a 
direction that will ultimately compel all 
watch manufacturers to depend upon the 
perfection of their products to secure to them- 
selves the confidence of dealers. 

Or. A. L., Gal. — "We do not know how the 
crimson watch hands of commerce are manu- 
actured, but you can produ3e the desired color 
by using any lacquer colored to the tint re- 
quired by dragon's blood, or by aniline color; 
apply with a soft camel hair pencil. An ex- 
cellent red lacquer is made of 8 parts (by 
weight; good alcohol, lpart dragon's blood, 3 
parts Spanih anatto, 4| parts gum sandarack, 
2 parts turpentine. Digest (with frequent 
shaking; for a week; decant, and filter; must 
be kept close. In some localities it is dif- 
ficult to get pure alcohol — and let us say in 
parenthesis, that the failure of many an ex- 
periment and receipt is due to the want 
of puro_ material. Common alcohol may 



be rendered nearly pure by putting a pint 
in a bottle, which it will fill only about three- 
fourths full ; add to it half an ounce of hot 
powdered pearlash or salt of tartar; shake 
the mixture frequently during half an hour, 
before which time a considerable sediment, 
like phlegm, will separate from the spirits, 
and it will appear along with the undissolved 
pearlash or salt at the bottom of the bottle. 
Pour the spirit off into another bottle, being- 
careful to bring none of the sediment with it. 
To the quantity just poured off add half an 
ounce of pearlash powdered, and heated as be- 
fore, and repeat the same treatment. Continue 
to do this until you obtain little or no sediment. 
"When this is the case an ounce of alum pow- 
dered, and made hot, but not burned, must 
be put into the spirits, and allowed to remain 
some hours, the bottle being frequently shak- 
en during that time ; after which the spirit, 
when poured off, will be found equal to the 
best rectified spirits of wine. 

A. F. O, N. Y. — It is not necessary to 
alloy iron castings or coat them with any 
other metal for the purpose of giving them 
the appearance of bronze. After having care- 
fully and thoroughly cleaned the article, give 
it a uniform coating of some vegetable oil ; 
sweet oil is as good as any, and more readily 
obtained than most others. Having done 
this, expose it, in a furnace, to a high tem- 
perature, taking care not to carbonize the oil. 
By this means the casting absorbs the oxygen 
at the moment when the oil is decomposed, 
and forms on its surface a thin coating of 
oxide, which adheres very strongly to the 
metal. It is susceptible of a high polish, and 
presents the appearance of a beautiful bronze. 

$3f We have received from Mr. E. L. 
May, of Defiance, Ohio, an illustration of his 
method of keeping his watch register. His 
day-book does not differ materially from 
those in general use by the trade, but he has, 
in addition, what he calls a ledger, into which 
are posted, in a very comprehensive manner, 
the items in the journal, making the ledger 
very convei ient for reference, and showing 
for the week or month at a glance the amount 
of his watch-work. The customers, as well 
as himself, are protected by a system of 
numbered tickets or checks, which insures 
safety from loss. 



96 



AMERICAN SEROLOGICAL JOURNAL. 



H. P. F., N. Y — Many experiments have 
been made to try the tenacity of various 
metals. The results — as measured with a 
spring balance — we give below : Two wires 
(No. 23) were used. The weight which broke 
these wires was — for tin, 7 lbs. ; for lead, 7 
lbs. ; for gold, 25 lbs. ; for copper, 30 lbs. ; 
for silver, 50 lbs. ; for iron, 90 lbs. ; for ahoy 
of lead and tin, 7 lbs. ; for alloy of tin and 
copper (12 lbs. to 100 of copper), 7 lbs. ; for 
alloy of copper and tin (12 lbs. to 100 tin), 
93 lbs.; for alloy of gold and copper, 75 lbs. ; 
for alloy of silver and platina, 80 lbs. ; for 
steel, 200 lbs. 

A. L. C, Phila. — We hardly know what one 
you refer to. In the Museum of the St. Peters- 
burg Academy of Sciences there is carefully 
preserved a watch said to be made by a mar- 
vellously inspired Russian peasant. It played 
two airs, and moved figures, although no 
larger than an egg. It was a repeater, too, 
and had a representation of the tomb of 
Christ, with the Roman sentinels on the 
watch. On pressing a spring, the stone would 
roll away from the tomb, the sentinels fall 
down, the holy women enter the sepulchre, 
and a chant would be played. This is the 
only one we know of claimed to be the pro- 
duct of inspiration. 

A. S. M., Mass. — We know no instrument 
that will give you the strength of hair-spring 
necessary for a watch when the weight of bal- 
ance, and the number of vibrations per min- 
ute, are known ; such a contrivance would be 
exceedingly useful. The only hair-spring 
gauge in general use is Bottom's. 

AMERICAN SEROLOGICAL JOURNAL, 



PUBLISHED MONTHLY BY 



o 



B_ MILLER, 

229 Broadway, K. T., 
At $9.50 per fear, payable in advance. 

A limited number of Advertisements connected 
toith the Trade, and from reliable Houses, will be 
received. 

B@°" Mr. J. Herrmann, 21 Norlha npton 
Sjuare, E. C, London, is our authorized Agent 
for Great Britain. 

AH communications should be addressed, 
G. B. MILLER, 
P. 0. Box 6715, New York. 



EQUATION OF TIME TABLE. 

GREENWICH MEAN TIME. 

For October, 1870. 



M 




Sidereal 














Time 


Equation 






Sidereal 


is 




of 


of 


Equation 




Time 


o 


Day 


the Semi- 


Time to he 


of 




or 




of 


diameter 


Subtracted 


Time to he 




Right 


<** 
o 


Mon. 


Passing 
the 


from 
Apparent 


Added to 
Mean Time. 


Hour. 


Ascension 
of 






Meridian. 


Time. 






Mean Sun. 






8. 


M S. 


M. 8. 


8. 


H. M. S. 


Sat 


1 


61.36 


10 18.72 


10 18 86 


0.797 


12 40 3.86 


Sn. 


2 


64.41 


10 37.66 


10 37.80 


0.785 


12 44 0.41 


M.. 


3 


64.46 


10 56.30 


10 56.44 


0.771 


12 47 56.96 


Tu. 


4 


64 51 


11 14.64 


11 14.78 


0.758 


12 51 53.51 


W. 


5 


64 56 


11 32.67 


11 32.81 


0.744 


12 55 50.07 


Th. 


6 


64.62 


11 50.33 


11 50 47 


0.728 


12 59 46.62 


Fri 


7 


64.68 


12 7.61 


12 7.75 


0.712 


13 3 43.17 


Sat 


a 


64.74 


12 24.48 


12 24.62 


0.695 


13 7 39.72 


Sn. 


9 


64.80 


12 40.93 


12 41.07 


0.677 


13 11 36.28 


M.. 


10 


64.87 


12 56.93 


12 57.07 j 0.659 


13 15 32.83 


Tn. 


n 


64.94 


13 12.45 


13 12.59 


0.638 


13 19 29.38 


W 


12 


65 01 


13 27.48 


13 27.63 


0.617 


13 23 25.94 


Th 


13 


65.09 


13 42.00 


13 42.14 


0.594 


13 27 22.49 


Fri. 


14 


65 17 


13 55.98 


13 56.11 


0.571 


13 31 19.04 


Sat 


15 


65.25 


14 9.41 


14 9 54 


0.547 


13 35 15.60 


Sn. 


16 


65.33 


14 22.25 


14 22.38 


0.523 


13 39 12.15 


M.. 


17 


65.42 


14 34.50 


14 34 63 


0.498 


13 43 8.70 


Tu. 


18 


65 51 


14 46 14 


14 46.27 


0.472 


13 47 5.26 


W. 


19 


65 60 


14 57.15 


14 57.27 


0.446 


13 51 1.81 


Th. 


20 


65.69 


15 7.51 


15 7.62 


0.419 


13 54 58.36 


Fri 


21 


65 79 


15 17.22 


15 17.32 


391 


13 58 54.92 


Sat 


22 


65.88 


15 26 25 


15 26 34 


0.362 


14 2 51.47 


Su 


23 


65.98 


15 34 59 


15 34.67 


0.333 


14 6 48.02 


M. 


24 


66.08 


15 42.24 


15 42.32 


0.304 


14 10 44.58 


Tu. 


25 


66 19 


15 49.19 


15 49.26 


0.275 


14 14 41.13 


w. 


26 


66 29 


15 55.43 


15 55 49 


0.245 


1418 37.69 


Th. 


27 


66.40 


16 0.93 


16 0.99 


0.214 


14 22 34.24 


Fri. 


28 


66.51 


16 5 69 


16 5.74 


0.183 


14 26 30.79 


Sat 


29 


66.62 


16 9 71 


16 9.75 


0.152 


14 30 27.35 


Su. 


30 


66 73 


16 12.97 


16 13.01 


0.120 


14 34 23.90 


M.. 


31 


66.84 


16 15.47 | 


16 15.50 


0.088 


14 38 20.46 



Mean time of the Semidiameter passing may be found by sub- 
tracting 0.18 s. from the sidereal time. 

The Semidiameter for mean neon may be assumed the same aa 
that for apparent noon. 

PHASES OF THE MOON. 

D. H. M. 

) FirstQuarter 1 9 19.2 

© Full Moon 9 142.9 

C Last Quarter 17 6 13.6 

® New Moon 24 3 35.7 

) FirstQuarter 30 20 1.2 

D. H. 

( Apogee 1121.5 

{ Perigee , . 24 16 . 5 

O / /' 

Latitude of Harvard Observatory 42 22 48 . 1 

h. m. s. 

Long. Harvard Observatory 4 44 29 . 05 

New York City Hall 4 56 0.15 

Savannah Exchange 5 24 20 572 

Hudson, Ohio 5 25 43.20 

Cincinnati Observatory 5 37 58 . 062 

Point Conception 8 1 42 . 64 

APPARENT APPARENT MERID. 

R. ASCENSION. DECLINATION. PASSAGE. 

D. H. M. S. o ' j H. M. 

Venus 1 11 29 28. 42....+ 4 51 28.7 22 50.0 

Jupiter.... 1 5 43 19.72.... +22 49 56.1 17 0.6 

Saturn... 1 17 29 29.26.. .. -22 16 25.6 4 48.7 



AMERICAN 





Vol. II. 



NEW YOKK, NOVEMBEK, 1870 



No. 5. 



CONTENTS. 

Invention, 97 

Heat, * 99 

The Lever Escapement, 102 

Adjustments to Positions, Etc., 105 

Mr. Grossman's Mercurial Pendulum, . . . 108 

Files, 109 

A Compensated "Wooden Pendulum, . . . . 112 

Staking Tool, 113 

Benzine as a Substitute for Alcohol, . . . 114 

Taps and Drills, 115 

Pinion Measurements 115 

Repairing English Watches, 11G 

Fair of the American Institute, 116 

Answers to Correspondents, 119 

Equation of Time Table, 120 

* * * Address all communications for Horological 
Journal to G. B. Miller, P. 0. Box G715, New York 
City. Publication OJice 229 Broadway, Boom 19. 



INVENTION. 



Thousands of vigorous, inventive minds 
are "wearing themselves out planning and de- 
vising new combinations, new machines, and 
new compounds, and fortunes are spent, fond 
hopes blasted, friends wearied out, and 
homes made desolate by the fruitless labor of 
invention ; years of study and costly experi- 
ment result, perhaps, in an application for a 
patent on a really valuable discovery, credit- 
able alike to the inventive talent and the per- 
severing industry of the inventor, but all, 
alas, too late. When hope is soaring in the 
sunlight, its wings are suddenly palsied, and 
the light extinguished, by the information 
that the child of invention is a hundred or 
more years old. 

This deplorable result, so crushing to the 
hopes and fortune of the inventor, is no fault 
of his ; it is simply the result of ignorance of 
■what has been done long previous to his 
time. Had he been better informed, or shown 
his first conception to some one better 
posted as to what had transpired in the 
■world of invention, all these disasters might 
have been avoided, and the amount of men- 
tal labor thus lost turned in a direction where 
better results might have been obtained. 



Undoubtedly it is impossible for every inven- 
tor to be so well read as to know all that has 
heretofore been discovered. Not even the 
best read can say that there is no invention 
of which they are not informed ; but what- 
ever information can be obtained that bears 
upon the study under pursuit, wall be of de- 
cided advantage, and may result in averting 
the provoking result of re-discovering old in- 
ventions. 

We have seen recently several advances 
made in the direction of affording assistance 
to inventors. One is the publication of " 507 
Mechanical Movements."* Such a work can 
be eminently useful in two ways : one in 
showing what has been done, and the other 
by furnishing to the inventor's hand, ready 
made, the very devise he desires in some con- 
struction he is laboring on. The idea has 
also been advanced to create a museum of 
machinery ; not completed machines, which 
would be impossible, but a working model of 
all the various devices for producing me- 
chanical effects ; a collection where every 
known method of applying the principle of 
the lever is illustrated in working models, 
every plan for changing linear to rotary mo- 
tion, every invention for the accumulation of 
force, every means by which it has been 
transmitted, or its direction changed, etc., 
etc. Such a collection of models would be 
but an alphabet of machinery, from which 
the inventor could elaborate machines to an 
extent limited only by his inventive ability, 
and save his own mind the wear and tear of 
studying out means to produce such effects 
as he desired in his proposed constructions. 

We have been led into this channel of 
thought by the multifarious plans constantly 
brought to our notice for compensating pen- 
dulums. Not a week passes that does not 
bring a new solution of the problem ; very 

* Published by Brown, Coombs k Co., office of the "American 
Artizan," 189 Broadway, New Yo;k. Price, One Dollar. 



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AMERICAN HOROLOGICAL JOURNAL. 



few of them ought to be called new — most of 
them dating back as far as Graham and El- 
liott, and scarcely any possessing sufficient 
advantages over old ones to make them de- 
sirable. Could we spare the space, we think 
it would be useful to give a description and 
drawing of all the known forms, as a guide 
to investigation ; it might save many a man 
profitless brain-work — mental labor which he 
could spend in inventive research in paths 
not already well worn and dusty with pre- 
vious travel— in research which would have 
a better prospect of resulting in good to 
himself and the world. 

Escapements, also, seem to have received a 
very large share of attention; no branch of 
horological mechanics seems more seductive 
than this, and the quantity of escapements 
invented is endless ; every one seems gifted 
with the faculty of originating new ones, and 
there is probably not a single workman in the 
country but what has had a try at it. An old 
clockmaker once offered, on a wager, to invent 
a new escapement every morning before break- 
fast for a month. Inventions seem so easy to 
some minds ; they see no difficulties in the 
way ; everything is clear ; a few principles 
adhered to, and the thing is done. Let us 
see how it works. We will quote from Mr. 
Nicholson's observations, which are as appli- 
cable now as they were in 1798 : " We will 
suppose a very acute theorist, who is not him- 
self a workman, nor in the habit of superin- 
tending the practical execution of machinery, 
to have conceived the notion of some new 
combination of mechanical powers to produce 
a determinate effect ; and for the sake of 
p irspicuifcy let us take the example of a ma- 
chine to cut files. His first conception will be 
very simple or abstracted. He knows that 
the notches in a file are cut with a chisel 
driven by the blows of a hammer by a man 
whose hands are employed in applying those 
instruments, while his foot is exerted in hold- 
ing the file on an anvil by means of a strap. 
Hence he concludes that it must be a very easy 
operation to fix the chisel in a machine, and 
cause it to rise and fall by a lever, while a 
tilting hammer of the proper size and figure 
gives the blow. But as his attention becomes 
fixed, other demands arise, and the subject 
expanis before him. The file must be sup- 



ported on a bed, or mass of iron, or wood, or 
lead or other material ; it must be fixed, either 
by screws or wedges, or weights, or some 
other ready and effectual contrivance, and the 
file itself, or else the chisel with its apparatus 
for striking, must be moved through equal de- 
terminate spaces during the interval between 
stroke and stroke, which may be done either 
by a ratchet-wheel, or other escapement, or by 
a screw. He must examine all these objects 
and his stock of means in detail, fix upon 
such methods as he conceives most deserving 
of preference, combine, organize, and arrange 
the whole in his mind, for which purpose 
solitude, darkness, and no small degree of 
mental effort will be required ; and when this 
process is considerably advanced he must 
have recourse to his drawing-board. Meas- 
ured plans and sections will then show many 
things which his imagination before disre- 
garded. New arrangements to be made, and 
unforeseen difficulties to be overcome, will 
infallibly present themselves. The first con- 
ception, or what the world calls invention, 
required an infinitely small portion of the 
ability he must now exert. 

" We ^will 'suppose, however, that he has 
completed his drawings ; still he possesses 
the form of a machine only ; but whether it 
shall answer his purpose depends on his know- 
ledge of his materials; stone, wood, brass, lead, 
iron forged or cast, and steel in all its various 
modifications, are before him. The general 
process of the workshop, by which firmness, 
truth, and accuracy alone are to be obtained, 
and those methods of treatment, chemical as 
well as mechanical, which the several articles 
demand, these, and numberless others, which 
may either lead to success, or by their defi- 
ciency expose him to the ignorance or ob- 
stinacy of his workmen. If he should find 
his powers deficient under a prospect so 
arduous ; if he cannot submit to the severe 
discipline of seeing his plans reversed, and 
his hopes repeatedly deferred ; if unsuc- 
cessful experiment should produce anguish, 
without affording instruction, what then will 
remain for him to do ? Will he embitter 
his life by directing his incessant efforts, his 
powers and resources, to a fascr'nating object 
in which his difficulties daily increase, or will 
he make a strong exertion of candor and 



AMERICAN HOROLOGICAL JOURNAL. 



id 



fortitude which will lead him to abandon it 
at once *?" 

There are cases, however, in which the pro- 
foundest knowledge of primary principles and 
previous practice has not saved the inventor 
years of toil and millions of money ; neither 
is the voyage of invention always plain sail- 
ing and calm weather. The poor inventor, 
however differently he may think, is often not 
more sorely beset by difficulties than he who 
has money and mind at unlimited command. 
Knowledge sometimes gives great advantage 
to its possessor in the prosecution of inven- 
tion, and yet it sometimes leads one far astray. 
Bessemer was a remarkable illustration of this; 
scientific analysis had shown steel to be a 
compound of carbon and iron, in proportions 
which might vary from forty to two hundred 
per cent, and yet be merchantable steel; and 
cast or pig iron differed from steel only by 
containing more carbon; and that malleable or 
wrought iron was made so by entirely decar- 
bonizing the pig. The inference very naturally 
arose, that steel should be produced at some 
point short of total decarbonization ; and that 
instead of costing more than wrought iron, it 
ought to cost less. 

Reasoning upon all these fads, Mr. Bessemer 
assumed that stopping the decarbonizing 
process at the proper point was the thing ; 
and all there was to do to effect this de- 
sirable change was to stop the decarbonizing 
process at the proper moment. But, with all 
his science, he never succeeded in making a 
pound of merchantable steel. What was the 
matter ? Analysis of his product showed the 
proper percentage of carbon to form steel, 
but it was iron still. Failure followed failure, 
and any man with less means and perseve- 
rance would have given up the chase. Still he 
toiled on, and his researches brought him to 
the very method that experience had discover- 
ed and successfully practised for years, namely, 
to wholly decarbonize the iron and then re- 
carbonize. The first condition he accomplished 
by the hot blast, and the second by adding a 
definite quantity of spiegeleisen to supply the 
carbon necessary for conversion to steel. Had 
he known in the beginning all that he after- 
wards found out, years of expensive experience 
would have been avoided. The facts which 
are now known to have prevented his success 



at first are, that the pig iron contained other 
substances than carbon, which must be elim- 
inated before steel can be produced. Silicon, 
phosphorus, and sulphur maintain their hold 
upon iron with the greatest tenacity, and any 
known process by which they can be separa- 
ted, will also completely decarbonize the iron, 
which must of course be re-carbonized to pro- 
duce steel. The books taught only part of 
the process — practical experience, the rest ; 
but together they show clearly why steel can- 
not be produced cheaper than iron. 

Thus we see the necessity for theory and 
practice to go hand in hand, — and when 
the trinity is completed by the addition of 
money, they together form a foundation on 
which a superstructure of any extent may be 
built, which will not only be a glory in itself, 
but a blessing to the world. 



HKAT. 



NUMBER FOUR. 



INCREASE OF VOLUME IN SUBSTANCES BY HEAT DO 

METALS BECOME PERMANENTLY ELONGATED 

CHANGE OF THE ZERO POINT IN THERMOMETERS 

CONDUCTION AND REFLECTION OF HEAT FAMIL- 
IAR EXAMPLES — HEAT TRANSMITTED THROUGH 
MERCURY BY CONVECTION — REMARKS ON COMPEN- 
SATING PENDULUMS, ETC. 

It is a general, though not a universal law*, 
that when a metallic body increases in temper- 
ature it also expands in volume, or dilates, and 
that when it diminishes in temperature its- 
volume contracts, and that when restored to 
its original temperature it resumes its original 
volume, or nearly so. Under the same aug- 
mentation of heat, different solids expand 
very differently. Certain crystals, as flu or 
spar, aragonite, etc., expand more than any 
of the metals which are frequently marked 
first ; and the rate of the expansion of ice, 
could it be observed through the same range, 
is greater than that of any metal between 
32° and 212°, being one part in 287- Wood 
expands chiefly in a direction transverse to 
its fibres, and very little in length ; and hence 
wood, as well as lucullite (a species of marble 
found in Egypt), has been used for pendulum 
rods. The contraction of bodies upon cooling 
is sometimes not so great as their previous 
expansion — perhaps it is never so. great.. Heat 



100 



AMERICAN H0R0L9GICAL JOURNAL. 



expands bodies by insinuating itself between 
the particles of these bodies, forcing them 
asunder, and causing them to occupy a greater 
space. Heat, therefore, opposes cohesion. 
Solids, in which cohesion is strongest, expand 
the least under the influence of heat ; liquids 
having less cohesion expand more ; gases and 
vapors, in which cohesion is entirely wanting, 
expand most. Clay may be taken as an 
exception to heat expanding all solids ; it is 
contracted by baking, and ever afterwards 
remains so ; this is supposed to be owing 
to a chemical change produced in the clay 
by heat. It is certain that under pecu- 
liar conditions some metals become per- 
manently elongated by repeated heating. 
The familiar example of the old bars of a fire 
grate, when they are rigidly fastened at both 
ends, becoming distorted, as we often see 
them, as well as another household example 
of lead pipes conveying hot water, have been 
found lengthened and thrown into curves after 
several weeks' use, does in a great measure 
prove this. Some of our readers would prob- 
ably notice in No. 11, Vol. I., a correspond- 
ent suggests that this permanent elongation 
of metals through the influence of heat might 
be the cause of some of the irregularities of 
pendulums, especially the Harrison one. 
Whether this permanent elongation of metals 
takes place in the comparatively small changes 
of temperature which a pendulum is subjected 
to, as it sometimes does in metals subjected 
to a boiling, or appx-oaching to a melting heat, 
we have not as yet any reliable means of 
ascertaining, although we have given the sub- 
ject much attention. "We have never observed 
any case, or heard of any complaint or well 
authenticated instance, where fine clocks have 
increased their losing rate in the same ratio 
as the clocks increased in age, which would 
be the natural result to be looked for, were 
the metals which compose the pendulum 
affected in the above manner ; still, the idea 
we consider is one worthy of the attention of 
those who are studying this important sub- 
ject, as it is evident that for the higher class 
of purposes the very best pendulums have yet 
to be improved. 

The fact of bodies or metals, when exposed 
to very high temperatures, not resuming their 
former bulk when cooling, may be attributed 



to the fact that when they are cooled very 
suddenly, in most cases their particles have 
not had time to bring themselves into the 
condition proper to the reduced temperature, 
and in consequence the substance is in a state 
of constraint, and continues so often for a 
length of time. This is probably the cause of 
the change of the zero point in a mercurial 
thermometer, for when such an instrument 
has been graduated shortly after the filling 
of the bulb, this poirt may change in a few 
years as much as nearly 3° Fahr., but this is 
believed to be the full limit of the change. 
When an instrument is made and filled, the 
bulb is suddenly heated and suddenly cooled, 
and hence its particles ha\e not had time to 
approach so near to one another as they 
would have done if the process of cooling ha 1 
been very gradual; and had the bulb been 
laid past and kept for some time before gra- 
duation, and also had it been well annealed, 
the change would have been less ; neverthe- 
less, with all this precaution the error may 
amount in the course of five or six years to 
several tenths of a degree. Besides this pro- 
gressive and permanent change, there is also 
a temporary one produced by heating and 
suddenly cooling the instrument when in ac- 
tual use. For example, if a thermometer has, 
first of all, its freezing point determined by 
melting ice, then be plunged into boiling 
water, and suddenly withdrawn, and finally 
again plunged into the ice water, the freezing 
point will be found to have changed, and the 
instrument may read 31.8° and will not re- 
cover its true reading till several weeks have 
elapsed. The same kind of error may be 
introduced into the barometer, when the sys- 
tem is practised of boiling the mercury in th i 
tube to drive the air out. We have frequently 
noticed steel articles become sensibly larger 
after being hardened, and it is well known t) 
all workers in glass and metals that the 
articles we form from the heated or molten 
material require to be very carefully an 1 
slowly cooled or annealed in order to brinjf 
them to their solid state, or their natural 
density ; and thus it appears that time is aa 
important element in the cooling of bodi ■ \ 
and with this reservation it may not pei/.apt 
be erroneous to assert that a metallic bodj 
heated and very slowly cooled will regain it* 



AMERICAN HOROLOGICAL JOURNAL. 



101 



original volume on regaining its original 
temperature. 

Having made some allusion in this article 
to the question of compensating a pendulum 
as near as possible to perfection, the present 
mar, perhaps, be a proper time to notice 
some other points to be considered in con- 
nection with this important subject. In last 
number we noticed how heat was conveyed 
through metals by conduction. The follow- 
ing table, showing the capacities of several 
of the metals for conducting heat, is taken 
from Professor Tyndall's work on Heat, con- 
sidered as a mode of motion : 



Silver 

Gold 


100. 
74. 
53. 
24. 
. 15. 
12. 


Lead 

Platinum 


11.7 
9. 

. 8. 


Tin 


German silver. . 


. 6. 
2. 



This table differs from many of the older 
ones published, which up to late years were 
accepted as correct, in which gold was con- 
sidered to be the best conductor of heat, and 
platinum and silver the next in order, being 
considered very little inferior to gold. How- 
ever the process by which the authors of this 
table have res ched the above results differed 
essentially from their predecessors in that 
line of experiment, and is entirely devoid of 
any theoretical assumption, being reached by 
actual experiment with the aid of a small 
thermo-electric pile, the most delicate and 
accurate of all known instruments for meas- 
uring heat or testing its progress through 
bodies. As all metals have a certain capacity 
for conducting heat, so have they for reflect- 
ing it under favorable conditions of their sur- 
faces. Highly polished and light colored 
surfaces reflect best. For instance, fire irons, 
if brightly polished, will remain comparative- 
ly cool, notwithstanding their proximity to 
the fire, while if rough and unpolished they 
will become too hot to be touched. Water 
contained in a burnished silver pitcher can with 
difficulty be heated, even while placed directly 
before the fire, while the same amount of 
water in a rough iron kettle at an equal dis- 
tance from the fire would speedily be made 
to boil. Nor is it necessary that the protect- 
ing surface should be of any great thickness. 



The thinnest coating of a bright metal reflects 
heat as perfectly as a solid metallic plate of the 
same metal. A mere covering of gold leaf 
will enable a person to place his finger within 
a very short distance of red hot iron or otlu r 
red hot metal, while the hand would be burned 
at ten times the distance, if unprotected. If 
a piece of red hot iron be held over a sheet 
of paper upon which some letters have been 
gilded, the uncovered intervals will be scorched 
while the letters will remain untarnished. 
If the bulb of a thermometer be covered with 
tin foil it will remain comparatively unaffected 
by change of temperature. The polished 
metallic helmet and cuirass worn by soldiers 
are cooler than might be imagined, because 
the polished metal throws off the rajs of the 
sun, and cannot easily be raised to an incon- 
venient temperature. Taking advantage of 
these properties for the reflection of heat off 
metals, Mr. John Gowans, a partner in the 
firm of Blunt & Co., of this city, has for some 
time past been coating his pendulums with a 
thin covering of nickel. This, as our readers 
are aware, presents a bright whitish surface, 
susceptible of a very high polish, and conse- 
quently presents the most favorable surface 
for the reflection of the heat from off the 
pendulum, and has also the additional prop- 
erty of being unaffected by rust should the 
clock be placed in a situation liable to damp- 
ness. 

Having every thing in its favor, with no 
counteracting disadvantage, we hail this as 
an important step in the right direction 
towards destroying some of the causes of the 
many little errors that are in all pendulums, 
and that only appear visible in clocks of the 
very best construction, where the larger errors 
do not exist to drown the small ones. 

Another important point in connection with 
the mercurial pendulum is the capacity of 
mercury for conducting or conveying heat. 
We have taken considerable pains to deter- 
mine exactly the value of the conducting 
power of mercury. In all the chemical author- 
ities we have at our command, both in the 
English and French languages, we never meet 
with mercury in the tables of the thermal 
conductivity of heat; for, mercury being a 
liquid, heat is conveyed through its particles 
by convection, and convection depends upon 



102 



AMERICAN HOROLOGICAL JOURNAL. 



two things. In the first place it depends on 
the extent liquids expand under heat ; thus, 
for instance, if a body hardly expanded at all? 
its convection -would be very feeble. In the 
second place, convection depends on the 
force of gravity ; for were there no gravity 
there could be no convection. We have no 
direct means of ascertaining exactly the capa- 
city of mercury for conveying heat ; but if we 
reason from analogy, and assume that the 
density of metals bear a relation to their 
powers of conduction, and also that the prop- 
erties for conducting heat and electricity are 
nearly the same in all metals, then mercury 
must be a very good conductor of heat ; prob- 
ably as good as silver or copper. It seems 
to us that this fact of heat being transmitted 
by conduction through steel, and by convec- 
tion through mercury, has an important bear- 
ing on the calculations of a mercurial pendu- 
lum, and in some measure affects the 
compensation as regards the time each body 
takes to expand or to contract ; and this idea 5 
so far as we are aware, is a new one. 

The expansion and contraction of the jar 
that holds the mercury, and somewhat affects 
the rise and fall of the mercury column, being 
difficult to correctly determine, we will con- 
clude the present article by presenting a 
method by which this object may be accu- 
rately obtained, which is also new for this 
purpose. Take a glass jar of a given size and 
cleanse it thoroughly, and fill it with mercury, 
without air specks being in any part of it. 
The jar will be found to hold, at 32° Fahr., 
say 10169.3 grains of mercury (about the 
amount used in a heavy seconds pendulum), 
while at 212° it only holds 10011.4 grains. 
Now it is known that the expansion of mer- 
cury between 32° and 212° is .018153 ; that 
is to say, a quantity of this fluid occupying a 
given volume equal to unity at 32° will at 
212° occupy a volume =1.018153. Hence the 
weight of mercury occupying a given volume 
at '212°, will bear to that occupying the same 
volume at 32°, the proportion of 1: 1.018153; 
and hence (had the jar not expanded) the 
weight of mercury filling it at 212° would 

-J ai n(\ o 

have been 1 01al5a = 9987.9 grains. But the 

glass jar having expanded, it holds 10011.4 
grains, or 23.5 grains more than it would have 



held had there been no expansion. The 
volume of the expanded jar will therefore 
bear to that of the same jar at 32 p , the ratio 
of 10011.4 to 9987.9, or of 1.00235 to 1 ; and 
hence the expansion of the jar between 32° and 
212° will be .00235. 



THE LEVEE ESCAPEMENT. 



NUMBER TWO. 

The action of the lever and roller is that 
action of the mechanism of the lever escape- 
ment which communicates to the balance the 
motion created by the wheel and pallet, as 
described in the preceding article on this 
subject. There are many ways of accom- 
plishing this action ; but as we intend strictly 
to adhere to the rule of giving the princijiles 
of this escapement, for the reasons previously 
mentioned, we will content ourselves by giv- 
ing the two most common forms of accom- 
plishing this action, viz.: that having the 
ruby pin and safety roller in one piece, com- 
monly called the table roller, and that having 
the ruby pin and safety roller in two pieces, 
commonly termed double roller. The action 
of the lever and roller embodies two distinct 
functions — that of propulsion, and that of 
imlocking — which will be better understood 
from the following description : 

The lever, being solidly joined to the pallet, 
forming, as it were, one piece, is forced to 
communicate the impulse derived from the 
action of the wheel on the pallet to the 
balance, by means of the ruby pin, acted upon 
by the slot in the lever. If we suppose the 
ruby pin to have been carried to the extreme 
degree of the lifting arc on either side of the 
lever (that is, if the drawing tooth has already 
dropped from the driving plane on either arm 
of the pallet), the balance will then be de- 
tached from the other parts of the escape- 
ment, and will be free to make its entire arc 
of vibration, effected by the impulse derived. 
This is the function of impulsion. The di- 
mensions of the arc of vibration will be com- 
paratively equal to the weight of the balance 
and the strength of the hair-spring. 

When the balance has reached the extreme 
degree of the arc of vibration, it will be 



AMERICAN HOEOLOGICAL JOURNAL. 



103 



acted upon by the tension of the hair-spring, 
thereby causing a return vibration of the 
balance. As soon as the ruby pin touches 
the slot, the lever, and, necessarily, the pallet 
along with it, follow the impulse far enough 
to withdraw the locking face, on which a 
tooth is resting. The tooth thus released 
begins its impulse on that arm of the pallet, 
and which is, of course, communicated to the 
balance by the lever and the ruby pin. The 
impulse continues until the tooth has slid 
across the face of the driving plane, and 
dropped therefrom on to the other arm of the 
pallet — which action is continuous. From 
this it will be seen that the action of the 
lever and roller is alternately to communicate 
impulse derived, and to unlock. As the 
watch is subject to almost continual external 
motion, it is therefore of the greatest im- 
portance to provide a means by which the 
lever, when at rest, may be kept in position, 
so that when the return vibration of the 
balance brings the ruby pin to 'the place 
where the connection is to be made, it may 
not find a vacant place ; the lever, meanwhile, 
being on the opposite side, and the ruby pin, 
instead of working into the slot, striking the 
outer edge of the lever, causing the watch to 
slop, and very likely a breakage of the ruby 
pin, and giving rise to the expression " over- 
banked." (From this it will be seen that 
when the roller is too small, overbanking will 
result. ) The prevention of this is called the 
safety action, and consists of a perfectly 
round disk of steel, having a hollow filed in 
it directly above the ruby piu, and is solidly 
adjusted to the balance staff ; and a pin or 
abutment on the lever placed immediately 
above and in the centre of the slot. The 
action of this is obvious. The lever being at 
rest on either side, it will remain so by the 
pin striking the edge of the roller when dis- 
turbed by violent external motion, but imme- 
diately returning from such position by the 
action of the " draw," as described in the 
previous article. The action of tho " draw," 
if not properly controlled, would also bring 
the lever out of position, but in a contrary 
manner to that of the safety action, by caus- 
ing the lever to pass out of reach (for con- 
nection ) of the ruby pin on a return vibration 
of the balance from the roller. This means 



of control is termed the " banking " arrange- 
ment, and consists of two pins, placed at a 
proper distance from each other, equally on 
each side of the lever, so that the lever will 
be enabled to give the whole amount of im- 
pulse derived, and yet not pass out of reach 
of the ruby pin on its return vibration. 

The original lever escapement, as invented 
by Mudge, had the ruby pin and safety roller 
composed of two pieces. At one time this 
was supposed not to be a very good arrange- 
ment, consequently the table roller was sub- 
stituted. Later, however, the original plan 
was adopted as the best for the purpose de- 
signed. The reason why the safet} r roller and 
the ruby pin is best in two separate pieces is 
thus : the safety roller, in this instance, being 
always one-third the diameter of the ruby 
roller, is affected far less by external motion 
than the roller and the ruby pin in one piece, 
for the safety roller being smaller, the fric- 
tion occasioned by the safety pin rubbing 
against the edge of the safety roller, when 
disturbed by external motion, will be lessened, 
as the friction is applied at a less distance 
from the balance centre. 

Our task will now be to determine the size 
of the roller (in both instances), the place for 
the ruby pin, the size of the lever, etc., etc., 
for any given distance of centres, considering 
first the one having the ruby pin and safety 
roller in one piece. 

First determine the distance between the 
centre of lever and centre of balance, in- 
crease the dimensions by ten or fifteen times, 
and connect them by line K, as in Fig. 1 ; 
then take 11|°, the whole movement of lever 
or pallet (as determined in the preceding 
article), and draw half of this, 5|°, on each 
side of the line K from the centre of lever B, 
and mark the lines t. Next, determine the 
lifting angle of the balance, which, in this 
case, as an example, is 40°, and which proceed 
to draw from the centre of balance A to 20° 
each side of the line K,and mark the lines thus 
drawn g; from where the lines g cross the 
lines t, draw a circle I, which indicates the 
place for the ruby pin n. Next proceed to 
determine the breadth of the ruby pin, which 
in all cases must be one-third the space be- 
tween two teeth of the escape wheel. To de- 
termine the working sides of the slot in the 



10 i 



AMERICAN HOROLOGICAL JOURNAL. 



level', draw a curve m from the centre of lever 
B, so that it will cross the point where the 
lines t and g, and the circle /, cross each other, 
which indicate the place where the horns of 




the lever u are to be drawn from, and are to 
be drawn thus : From the centre of lever B 
mark off the dots p, 1|° distant from the lines 
/, and place one leg of the compass on one of 
these dots, and draw the curve u of the op- 
posite horn, proceeding in like manner with 
the other horn. 

To determine the actual length of the 
lever, that is from the point or abutment r 
to the centre B, the hollow in the roller for 
the passage of the abutment r must be above 
the ruby pin far enough to allow the latter 
to sit solidly in its place, and must have a 
breadth of 10° or 12°, and the point of the 
abutment r must be 1° or 1^° distant from 



the deepest part of the hollow, which we de- 
termine by the curve b drawn from the centre 
of lever B, as shown in the figure, and from 
the point where the lines t cross the curve b 
we draw the circle or roller R. Now proceed 
to determine the place for the banking pins 
or abutments q, the positions of which are en- 
tirely dependent upon the shape of the lever. 
The easiest way to determine this i3 to sup- 
pose the ruby pin to be carried around to a 
point where the abutment r will rest on the 
roller R ; in such a position 1|° or 2° distant 
(requisite shake) from the outer edge of the 
lever s will give the proper place for the 
banking pins or abutments. 

We will now consider the lever and roller 
action, having the ruby pin roller, and safety 




roller separate. First, fix upon the distance 
between the centre of lever and centre of bal- 



AMERICAN HOROLOGICAL JOURNAL. 



1C5 



lance, increase the dimension ten or fifteen 
times, and mark on paper A and B, connect- 
ing them by line K, Fig. 2 ; take the whole 
movement of the lever (or pallet), 11|°, and 
draw them from the centre of lever B, 5|° on 
each side of link K, and mark t. We propose 
the lifting angles to be 40°, which are drawn 
from the centre of balance A, 20° on each 
side of the link K and mark g; from the point 
where the lines g cross the lines t we draw 
a circle /, which, indicates the place for the 
ruby pin n, which must be one-third the 
space between two teeth of the escape wheel ; 
then mark off the dotsjp, 1° distant from the 
lines t, on a curve through the balance centre 
A from the lever centre B. To determine 
the slot in the lever, draw a curve m from 
the lever centre B, so that it will cross the spot 
where the lines t and g and the circle I cross 
each other ; the slot should have a breadth 
1° greater than that of the ruby pin (requi- 
site play), and is marked off on the curve m, 
from these points are drawn the curves u 
from an opposite dot;;, forming the horns of 
the lever. 

We next determine the actual size of the 
lever — that is, from the lever centre B to the 
point of the safety pin n, thus : the diameter 
of the safety roller w being § that of the ruby 
pin roller R, it will therefore require a hollow 
of 36° to 38° for the safe passage of the safety 
pin r (the safety roller being smaller and the 
lever larger); from the point where the lines 
t eross the circle or safety roller xo, draw from 
the lever centre B a curve b ; the spot where 
this curve crosses the line K is the place for 
the point of the safety pin or abutment r; the 
deepest part of the roller must be 1° from 
the point r. The method of determining the 
proper place of the banking pin q, is the same 
as in Fig. 1. To determine the actual size of 
each part, it only remains to diminish each 
part as many times as the original centre 
distance was increased. 

It is deemed unnecessary to give the com- 
bination of the action of lever and roller with 
that of wheel and pallet, as there are so many 
of these combinations, each differing from 
the other ; some having the pallets at right 
angles from, and others in a line with, the 
lever, while others are placed at some other 
angle ; but it matters not whether it be at 



right angles or in a straight line ; the prin- 
ciple is always the same, and can in no way 
be altered by any angularity of the pallet to 
the lever. There are many repairers imbued 
with the idea that the so-called straight bne 
lever is the best, as the best watches with this 
escapement are planned straight line. This 
is erroneous,]as they are so planned only be- 
cause it makes an elegant appearance. 

Charles Spiro. 



ADJUSTMENTS TO POSITIONS, ISOCHUONISM 
AND COMPENSATION. 



NUMBER ONE. 



The importance of a thorough apprehen- 
sion of the principles involved in seeking for 
the above adjustments, and the interest which 
is everywhere felt among the trade concern- 
ing them, must be the writer's excuse for so- 
liciting the attention of the readers of the 
Journal. 

In reasoning upon these subjects, the theme 
of articles already published in the columns 
of the Journal, and particularly in the contri- 
butions of Chas. Spiro, for which Ave would, on 
behalf of the trade express our grateful ac- 
knowledgments, we do not propose to present 
anything original or new — anything which 
nobody else knows — but shall simply endeav- 
or to investigate the principles involved in, 
and to copy and translate from the writings 
of eminent foreign horologists, and particu- 
larly from Prof. Phillips, Jurgensen and 
others, such data as will contribute to make 
the subjects clear and intelligible to the minds 
of those interested in them. 

The main principles of the isochronism of 
the hair-spring have already been clearly set 
forth by Mr. Spiro, but in our opinion, in or- 
der to obtain the bests results of isochroni&m 
the adjustment to position ought to precede 
in the order. There is nothing so necessary 
to the successful accomplishment of so tedious 
a work, as logical reasoning. Practical ho- 
rology is nothing less than a physico-mathe- 
matical science, and it becomes necessary for 
the workman to educate himself to the use 
of these sciences, if he does not wish to 
waste much time and talent. Although ^heo- 



106 



AMERICAN HOEOLOGICAL JOURNAL. 



reticaly, and according to Prof. Phillips, the 
isochronisin of a spring can be found without 
the application of an escapement,yet in practice 
this would hardly ever be done ; it is much 
more likely that that adjustment is undertak- 
en only with a watch in a finished state, and 
when every other part has been carefully 
brought to as near perfection as possible. The 
best writers, too, concur in the opinion, that, 
although by the application of an isochronal 
hair-spring to the balance any irregularities 
resulting from unequal friction in different 
positions could theoretically be entirely over- 
come, it is nevertheless of the greatest im- 
portance that those irregularities should first 
be removed as nearly as possible by a judici- 
ous adjustment to positions. If a lever watch 
is to be adjusted to positions, one of the first 
conditions necessary is, that the fork and 
lever, as well as the escape wheel be perfectly 
poised. On this point the opinions of all the 
best writers and most experienced artisans, 
such as J. H. Martens, M. Grossmann and 
others, agree ; and in fact in the best move- 
ments of foreign manufacture the condition 
is fulfilled ; but since there is such a great 
number of watches wanting this condition, 
and some of them the productions of highly re- 
putable manufacturers, and since even among 
our own home manufacturers the necessity 
of establishing the equipoise of the lever in 
their escapements seems to be partially over- 
looked, let us investigate the matter a little 
closer ; and for this purpose we beg leave to 
draw the attention of the reader for a moment 
to the principles of the mechanical lever. 

The simplest form of a lever is a straight 
rod, supposed to be inflexible and without 
weight, resting on a fixed point somewhere in 
its length, about which it can freely turn, and 
having two forces applied, one on each of the 
extremities of the rod. The fixed point on 
which it rests, and about which it can turn, 
is called the fulcrum ; one of the forces applied 
to it is called the poioer, and the other the 
weight. The distances of the points of appli- 
cation of the power and weight from the ful- 
crum are called the arms of the lever. If, 
now, we imagine such a lever in the shape of 
a beam thirteen feet long, and the fulcrum be a 
foot from one end, an ounce placed on the 
long arm will balance a pound [troy weight) 



on the short arm ; and the least additional 
weight, or the slightest push or pressure on 
the long arm thus loaded, will make the pound 
on the short arm move upwards. If, instead 
of a pound, we place upon the short arm of 
this lever the long arm of a second lever, 
whose fulcrum is one foot from its short end, 
and then place the short arm of this second 
lever upon the long arm of a third lever, 
supported by a fulcrum one foot from its end, 
and each of the three levers is thirteen feet 
long, then an ounce on the first lever's long 
arm will balance a weight of one hundred and 
forty- four pounds on the third lever's short 
arm. Now, let us apply the principle to the 
train of a watch ; each of the wheels and pin- 
ions of which are nothing more nor less than 
such levers ; the pivots being the fulcrum s, 
the radii of the pinions the short arms, and 
the radii of the wheels the long arms, and let 
us suppose the leverage power of each at 
equilibrium to be as 1 to 8, and further- 
more that the force of the main-spring actirg 
upon the short arm of the first lever (centre- 
wheel pinion) is as the weight of one pound, 
then one-eighth of a pound will balance it at 
the circumference of the centre wheel, -gL at 
the circumference of the third wheel, --i^ at 
the circumference of the fourth wheel, and 
4 ^9 e > or one grain and ^f of a grain at the 
circumference of the escape wheel. If now, 
the lever, together with the fork, should weigh 
three grains, and this weight be distributed 
so that two grains should be on one side of 
its axis and one on the other, it will be appa- 
rent that, while the unequal poise could net 
arrest the motive power, owing to the freedom 
of the lever on ii s axis, and the great purchase 
which it has upon the pallet arms, it would at 
least occasion very great irregularity in the 
transmission of it to the balance — in many 
cases endangering the lockings — and never 
could such a watch run in all positions alike. 
One of the consequences of unequal poise in 
the lever is, that the watch, though the hair- 
spring may be properly fastened, will always 
sound as if it were out of beat. We may, by 
reasoning in this way, not only be able to ap- 
preciate the evil consequences of unequal 
poise in the lever, but also the importance of 
making them as light as a certain solidity 
will permit. 



AMERICAN HOROLOGICAL JOURNAL. 



107 



But we will suppose a watch perfect iu this 
particular and proceed to investigate the 
means of adjusting it to position. So far as 
we know, two theories have been advanced on 
this subject ; the one resting upon the principle 
of governing the motion of the balance by 
means of the screws applied as compensating 
weights, the other upon that of equal friction 
in all positions. According to the former 
theory the balance is actually thrown out of 
poise in this way : when the watch goes fast 
in a hanging position, one or more of the 
screws of the balance which are on the top of 
it when it is in equilibrium and the watch is in a 
hanging position, is moved a little further out 
from the centre, which will cause the balance 
to describe greater arcs of vibrations in that 
position, and consequently make it go slower. 
Now it is evident that the advocates of this 
theory do not suppose an isochronal hair- 
spring to be in such a watch, and if that is 
the case the effect of such an operation might 
be a contrary one, for it might just as well 
happen that an increase of motion would make 
it go faster ; would the fact of its going faster 
in a hanging position indicate less friction ? 
and even were this operation to have the 
desired effect in that position, how would it be 
if the watch were reversed ? At best the 
practice is a violation of the law of the com- 
pensation balance — the perfect equipoise — 
which is most strongly inculcated, to advo- 
cate which no good workman should be guilty 
of doing. We propose to adjust a watch to 
position according to principles which shall be 
independent of, and not interfere with or 
destroy, any other adjustment in the watch ; 
and that we deem can only be done according 
to the principles of equal friction. 

Ernest Sandoz, in his " Practical Methods 
of Accurately Adjusting Watches," bases his 
theory on the same principles, but in his 
practice he goes equally wrong to effect an 
increase of friction, by throwing the hair-spring 
a little out of centre. It probably did not 
occur to him that he thus destroys an 
essential condition of the isochronism of the 
spring. 

We know of no better way of adjusting a 
watch to position than by the pivots of the 
balance. J. H. Martens gives the following 
rules for this adjustment, which in the main 



have already been mentioned by Mr. Spiro, 
but which we beg leave to repeat : 

" 1st. The pivots of the balance must have 
" the least possible diameter which the weight 
"and size of the balance will permit, must be 
" well hardened and polished so as to cause 
" the least possible friction in the jewel holes. 

" 2nd. Jewels with olive-shaped holes must 
" be used for the balance, in which the friction 
" is much smaller than in cylindrical ones. 

" 3d. The ends of the pivots must be made 
" almost entirely flat, by means of which the 
" friction in a horizontal position of the watch 
" can be made equal to that in a vertical 
"position. 

" 4th. It is necessary that the utmost care 
"be had in fastening the hair-spring to a 
" proper height from the balance, and its coils 
" regularly concentric to its axis, in order to 
"insure perfect freedom in its vibration." 

If these four conditions be carefully observed, 
we will endeavor to show that the adjustment 
can be accomplished by varying the third. 

This theory rests upon producing equal 
friction in all positions. If, then, we present 
equal surfaces of the pivots to friction, the 
object must be attained. The end of the 
pivot being flat, to know the area of surface 
it presents to friction, we must measure its 
diameter and multiply it by 3.14, and we will 
have the circumference of the pivot, which is 
also the circumference of the circle of the flat 
surface of the. pivot, the area of which we 
wish to know. Now, the area of a circle is 
equal to the circumference, multiplied by half 
its radius; and if we measure half the radius 
of the pivot on its length, it is evident that 
we have, on the circumference of the pivot, 
the same square area as on the flat end (if 
the pivots are'conical, full or more than twice 
this length on each must be perfectly cylin- 
drical) ; this would present an equal surface 
to friction, as well on the side of the pivot as 
on the end of it ; but when the watch runs 
in a horizontal position— that is, on the end 
of the pivot — the flat surface of the pivot rubs 
against an equal flat surface on the end stone; 
whereas, when it runs in a vertical one — that 
is, on the side of the pivot — the same surface, 
owing to the shape of the pivot hole, only 
rubs against a single point, and though this 
is in a measure balanced by two such sur- 



1 ; 



AMERICAN HOROLOGICAL JOURNAL. 



faces, one on each pivot, rubbing thus against 
points, nevertheless the friction in that posi- 
tion of the watch will be much less than on 
the end of the pivot, whereby the arcs of vi- 
brations of the balance will be increased. 

Now, before attempting to equalize the 
friction, the balance must be perfectly poised; 
and to test whether this condition is entirely 
established in it, it should be laid with its 
pivots on two upright steels, brought to a 
knife-edge, perfectly level and polished on 
top ; on such an apparatus, if a perfect equi- 
librium is not established in the balance, it 
will show itself — there being no friction in the 
rolling of the pivots on these edges— and 
must be corrected. All the preceding con- 
ditions being complied with, and the watch 
is running, observe the arcs of vibration in 
both horizontal and vertical position ; if they 
are greater in the vertical position, it indicates 
less friction, and this cannot well be increased 
in that position, or we do not wish to increase 
it ; we therefore decrease it in the horizontal 
position by rounding off the ends of the pivots 
a little ; each pivot must thus be separately ad- 
justed, until in all positions the arcs of vibra- 
tion are the same, which will indicate equal 
friction n all. It will be seen that we may thus 
approximate isochronism, even without estab- 
lishing it in the hair-spring, and experience has 
amply proved to us that a watch thus adjusted 
will, except under irregular external influ- 
ences, run in all positions very nearly alike. 

In the next number we purpose giving a 
translation of Professor Phillip's theory of the 
terminal curves necessary to establish isochro- 
nism. HOROLOGIST. 
o 

MR. GROSSMAN'S MERCURIAL PENDULUM. 

We have received from Mr. Grossman tho 
following diagram of his mercurial pendu- 
lum, as compared with the Graham pendu- 
lum, both being one-sixth the actual size of 
a seconds pendulum. 

He has also promised another article on 
the subject for the next number of the Jour- 
nal. We regret to learn that the state of his 
wife's health is such as to ieave no hopes for 
her recovery, and are sure that he will ie- 
ceive the sympathy of our readers as well as 
our own. 




AMEEICAN HOEOLOGICAL JOURNAL. 



109 



FILES. 

It may not be uninteresting to many of 
our readers to know something more about 
files than their use. They are very exten- 
sively manufactured at heme as well as 
abroad, and their commercial value is com- 
mensurate with their world-wide utility. 
There is scarcely any branch of manufacture 
where they are not required ; the humblest 
occupation can scarcely be continued without 
using a file of some form. 

The varieties of files are almost endless, 
depending as they do upon the uses they are 
to be put to. They may vary in length from 
those we use, say three-quarters of an inch 
to three feet and more. "Watchmakers' files 
are perhaps as varied in their form and char- 
acter as those of any other artisan, but they 
seldom exceed 4 or 5 inches in length. 
Mathematical instrument makers, gunsmiths, 
and those whose works are of medium size, 
employ files from 4 to 14 inches in length. 
The file is always measured exclusive of the 
tang, by which the file is fixed in its handle. 
Generally the lengths of square, round, 
and triangular files are from 20 to 30 
times their greatest width ; broad, flat, and 
half-round are from 10 to 13 times their 
width. 

Files are distinguished as taper, Hunt, and 
parallel. The taper are the most numerous, 
their length being made so as to terminate in 
a point ; the blunt are made nearly parallel, 
terminating in a square end. In both kinds, 
however, the section of the file is largest to- 
wards the middle, so that the sides are some- 
what arched or convex. A few files are made 
a3 nearly parallel as possible, and conse- 
quently have an equal section throughout ; 
such are called parallel files ; but even in 
these it is common to find them a little full 
in the middle. In almost all taper, blunt, 
and parallel files the central line is kept as 
straight as possible. Files used by sculptors 
anl carvers are made curvilinear in their 
central line, and are called riflers. 

Files, in other respects the same, may differ 
in the forms and sizes of their teeth. In the 
first place, they may be single-cut — that is, a 
number of ridges are raised straight across 
the file by one series of straight chisel cuts ; 



these are called floats. In the second place, 
files are double-cut — that is, two series of 
straight chisel cuts are made across each 
other, whereby an immense number of points 
or teeth are raised on the surface of the file ; 
such double-cutting makes them true files. 
In the third kind the surface of the steel is 
dotted over with separate teeth, formed by a 
pointed chisel or punch, and it is then called 
a rasp. Floats and rasps are made for woods, 
horn, and other soft material; files proper 
for metals and general purposes. The fol- 
lowing table gives the general cut of files and 
the names indicating- the cut : 





4 in. 
long. 


Gin. 
long. 


8 in. 
long. 


12 in. 
long. 


16 in. 
long. 


20 in. 
long. 


Rough 


Cuts, 
pcrin. 

5(5 

76 
112 
216 


Cuts, 

per in 

52 

64 

88 

144 


Cuts, 
per in 

45 

56 

72 
112 


Cut?, 
per in. 

40 

58 

68 

88 


Cuts, 
per in . 

28 

44 

64 

76 


Cuts, 
per in. 

21 

34 




56 
64 



To give the names and uses for all the 
various forms would require a volume, and 
we will stick to the trade, as far as possible. 

Taper flat files are rectangular in shape, 
considerably rounded on their edges, and 
somewhat also in their thickness; hence they 
are said to be bellied, and are in general use 
among all classes of mechanics. 

Flat or Hand files are rectangular in sec- 
tion, parallel in width, and a little taper in 
thickness. 

Cotter files are narrower than hand files, 
nearly flat on the sides and edges, used for 
filing grooves for keys or wedges in fixing 
wheels or shafts. 

Pillar files are somewhat narrower and 
thinner than flat hand files, and usually have 
one safe (uncut) edge. 

Half round are just what the name indi- 
cates, and are called/WZ half round and flat 
half round. 

Triangular are also called three-square, and 
are usually taper files. 

Crossing files, sometimes called double half 
round, have each face of a different curvature, 
and are useel for filing out the crosses, or 
arms, in small wheels — the opposite sides of 
the tool presenting a choice of curvature. 

Round files, when taper, are called rat tail, 
and when small, mouse tail, from their re- 



110 



AMERICAN HOROLOGICAL JOURNAL. 



semblance to those animals' appendages ; 
when parallel, they are called joint files. 

Square files are mostly taper, made both 
with and without a safe side. 

Equalling files are usually parallel in width, 
and always so in thickness ; when both sides 
are safe, they are called ward files. 

Knife files are usually taper, with one edge 
thin and the other thick. 

Slitting files have both edges thin. 

Pivot or Verge files are half square ; that is, 
their width is double their thickness, and are 
subdivided into right and left hand, accord- 
ing to the angle which the edge makes with 
the side ; in neither is it quite a right angle 

Potence files, and pillar files, are small flat 
hand files. 

Round-off files are half round, with the flat 
side cut, and the round side safe, and have a 
pivot on the end opposite the tang. 

The forging of file blanks is all done by 
hand labor, the workmen each confining 
himself to a certain kind of file, in order that 
by the concentration of his skill and attention 
he may attain speed and perfection in its 
manufacture. The rod of steel is raised to a 
heat, never exceeding blood red, in a coke 
fire, two persons working together at the same 
anvil— one called the maker, the other the 
striker. Three square and a half round are 
formed in grooved bosses or dies, fixed in the 
anvil. The forged blanks are carefully an- 
nealed to make them soft enough for cutting 
the teeth. Blanks for common files are 
softened in an ordinary annealing oven, but 
the best blanks are protected from the action 
of the air by being buried in sand contained 
in an iron box ; this is slowly heated to a 
blood red as in forging. The surfaces of the 
blanks are next made accurate in form, and 
clean in surface, by rough filing and grind- 
ing ; in some cases dead parallel files are 
planed in a planing machine. 

Next comes the cutting. The workman 
sits astride a low bench (usually stone) ; in 
front of him, at one end, is the anvil ; the file 
blank is held on the anvil by means of a 
leather strap passing over each end of it, and 
then under the feet of the workman, like 
stirrups ; the hammers weigh from one to six 
pounds according to the size of the file, and 
are curiously formed, the handle being so 



placed as to cause the mass of metal to be 
pulled toward the workman while making the 
blow. The chisels are formed of the best 
steel, and vary with tbe size of the file ; they 
are broader on the face than the width of the 




file, and are only just long enough to be held 
between the thumb and the forefinger of the 
left hand. At every blow of the hammer the 
chisel is made to cut a tooth, and the blows 
follow one another in such rapid succession 
that the movement forward of the chisel be- 
tween each blow is not perceived. When one 
surface is covered with single cuts, he pro- 
ceeds, in double-cut files, to add a second row, 
making them cross the first at a certain angle. 
When one side is fully cut, he proceeds to cut 
the other side ; but as the teeth just finished 
would be injured by placing them on the 
naked anvil, they are protected by interpos- 
ing a flat piece of alloy of lead and tin, which 
perfectly preserves the side already formed. 

Holtzapffel describes the operation in these 
terms : " The first cut is made at the point 
of the file, the chisel is held at a horizontal 
angle of about 55°, with the central line of 
the file as at a a in the figure, and with a ver- 
tical inclination of about 12° from the per- 
pendicular. The blow of the hammer upon 
the chisel causes the latter to indent and 
slightly drive forward the steel, thereby throw- 
ing up a trifling ridge or burr; the chisel is 
immediately replaced on the blank and slid 
by the operator until it encounters the ridge 
previously thrown up, which prevents it 
slipping further back, and thereby deter- 
mines the succeeding position of the chisel. 
The chisel, having been placed in its second 
position, is again struck with the hammer, 
each blow, by practice, being given with the 



AMERICAN HOKOLOGICAL JOUENAL. 



Ill 



same force. The drawing gives an enlarged 
view of the section of the file and chisel, 
showing very clearly the formation of the 
teeth. In making the second cut the chisel 
is inclined vertically as before, but only about 
5° to 10° from the rectangle, as at bb. 




Before being hardened, the files are drawn 
through beer grounds, yeast, or some ad- 
hesive fluids, and then through common salt 
mixed with pounded hoof; the object of which 
is to protect the teeth from direct action of the 
fire and oxidation by the air ; the fusion of 
the salt affording an index when the harden- 
ing heat is attained ; it is then immediately 
removed from the fire and plunged into a 
cistern of cold water. The method of plung- 
ing it in the water is of importance ; it is held 
by the tang with tongs, and immersed slowly 
or quickly, vertically or obliquely, according 
to its form ; experience only can teach that 
method which is most likely to keep the file 
straight. They are next scoured with brushes 
dipped in sand and water, then are put in 
lime water for some hours to get rid of every 
particle of salt ; they are then thoroughly 
dried at the fire, rubbed over with olive oil 
containing turpentine, and are then ready 
far packing. 

The manual dexterity displayed in file- 
cutting is scarcely excelled in any branch 
of art. In the great London Exposition, in 
the Danish department, were displayed a 
series of cast steel files that were almost fit to 
be classed among fine art ; one large square 
file was covered with a series of pictures, 
representing on one face a view of the city of 
Copenhagen, on another face the operations 
of the forge, file cutting, etc. 

These effects were entirely produced by the 
file-cutter's chisel; the effect of shading being 
given by the Aarious angles of the teeth 
reflecting the light at different degrees of 
obliquity. The teeth of a large circular file 
were cut so as to represent in a spiral going 
several times ai ound the file, the maker's 
name, wreaths, c"ate, etc. This file was hollow 



and co^ tained within it a second hollow file, 
which in its turn contained ten others, all orna- 
mented in a similar manner, the smallest 
being not larger than a needle. 

Machine-cut files are produced to some 
extent, but the difficulties attending the use 
of machines have prevented their serious 
interference with the hand work. The pro- 
per use of the file requires more dexterity 
than many suppose ; there are very few who 
can use a large file skilfully without long and 
tedious practice. A moment's consideration 
of the subject will show why. Suppose a 
piece of metal in the vise, an inch in thick- 
ness, to be filed square across ; to do this, the 
file must be drawn and pushed in a perfect 
plane, which seems easy to do, but on trying 
it you will find the leverage between the 
point and handle is constantly changing ; in 
the beginning of the cutting stroke the handle 
has all the advantage; at the middle of the 
stroke each hand, one at each end, are equally 
balanced; but as the file advances, the point 
gets the advantage of the long end of the 
lever ; the consequence of this condition of 
things is a great tendency to cut away the 
edge nearest you of the piece upon which you 
operate. In the last end of the stroke it is 
almost impossible not to tilt the point of the 
file downward, so as to cut away the far side 
of the piece ; consequently the surface filed 
becomes convex instead of flat. There is 
also another element of error which comes 
in ; both arms tend to swing on a curve, or 
rather on two curves — one centre being at 
the shoulder, the other at the elbow, and 
these compound circular motions are difficult 
to reduce in practice to the necessary straight 
line. The shapes of files would indicate that 
the cut would be concave, but the workman 
who can file a surface to fit the file is a rarity. 
By the diagram showing the enlarged view of 
the file-teeth it will be seen that they cut only 
in one direction — and the pressure, in using, 
should be applied only during the forwaid 
stroke, and the return stroke with barely suf- 
ficient pressure to keep the file in contact with 
the surface, the " flat" being kept more by the 
sense of touch than by reasoning or judg- 
ment. 

To use files economically, the first wear 
should come upon brass or cast-iron ; when 



112 



AMERICAN HOROLOGICAL JOURNAL. 



they commence to lose their keen edge, they 
can then come upon wrought-iron or steel, 
with almost as sharp a cut as at first ; if the 
first use be upon iron or steel, they are compar- 
atively valueless for cast-iron or brass after- 
ward. Six inch files, without handles, are 
no better than three inch ones properly 
handled ; for one half the file, in the first 
instance, is used as a handle, and the rear 
part is valueless, except to hold it by. It is 
a shiftless, wasteful method to use them thus, 
and when we see a bench strewn with handle- 
less files, we expect to find a careless, unthrifty 
workman. 

We have seen many receipts for recutting 
wornout files by acid, but have never suc- 
ceeded in accomplishing any great good by 
them. !,The best way is to take them to a file- 
cutter, then you have new files for old ones, 
at a trifling expense ; nearly all the principal 
cities now have such establishments ; cer- 
tainly every manufacturing place supports one 
or more of them. 

Many small files imported from the Con- 
tinent are simply iron, ease-hardened ; that 
is, the surface converted into a thin film of 
steel. Such files are used to a considerable 
extent by jewellers, for filing gold and such 
soft metals, and answer a tolerable purpose ; 
but for a watchmaker to buy such is a waste 
of money. English files have for years main- 
tained a reputation for superiority, but of late 
years certain makes of Swiss and French files 
have proved very excellent, and it would seem 
that a people who so extensively and skilfully 
use them ought to be equally successful in 
their manufacture. 



J5@°* We have received too late for this 
number, an article from Mr. J. Herrmann, of 
London, on the epicycloidal formation of 
wheel teeth by co-ordinates, but which will 
be presented to our readers in the December 
number, and can also promise an article 
from Mr. Grossmann in the same issue. Mr, 
Herrmann is doing a very valuable work in 
giving instructions in mechanical drawing 
to classes in connection with the Horological 
Institute, and we only regret that the young 
men in our own city could not avail them- 
selves of similar opportunities for improve- 
ment. 



A COMPENSATED WOODEN PENDULUM. 



Editor Horological Journ.il: 

Even if any of the various pendulums now 
in use was perfect, there would still be an 
occasion for discovering one that might be 
simpler and less expensive. 

The Graham pendulum— the best — re- 
quires a more costly material than any other, 
and the Gridiron, while open to the same ob- 
jection, on account of its construction, is a 
thing " fearfully and wonderfully made." 
These two are in general use in this country. 
The performance of the Graham is excellent, 
but it is not quite perfect. The performance 
of the Gridiron, when well made, is only or- 
dinary, while the least defect in its construc- 
tion is fatal to eve a ordinary time. 

The following description of a pendulum 
which approximates to the perfection of the 
Graham, at a merely nominal cost, will be so 
readily understood that any watchmaker can 
apply it and tjst it himself. The princi- 
)le upon which it is made has 
>een generally followed here- 
ofore in selecting the least 
ispansive material for the rod. 
2he rod in the present case is 
■I soft white pine wood, of 
•-ourse well seasoned and per- 
ectly straight in the grain. 
Che expansion or contraction 
>f this wood lengthwise is ab- 
olutely little or nothing. The 
■ob is the common brass shell 
died with lead, and is adjusted 
o time in the ordinary manner. 
Che rod is suspended by a 
ampered steel spring, which 
hould not be thick enough to 
under its very free vibration, 
nd for a seconds pendulum 
he working part of the spring 
leed not exceed in length | of 
,n inch. The compensation is 
>rovided for in the following 
nanner, viz. : A is a brass ball 
ree enough on the pendulum 
^o slide up or down without 
touching the rod ; B B are brass or zinc rods; 
upon the upper ends of these two rods the 
ball A is fitted loosely, and is adjusted up or 



AMERICAN HOROLOGICAL JOURNAL. 



113 



down by screw nuts traversing the rods. The 
Tower ends of the rods B are fitted into a col- 
let C that is fastened to the pendulum rod by 
a screw. The compensation ball should be 
placed nearly in its place on the rod and fas- 
tened by the screw in the collet C ; it may 
then be adjusted exactly to compensation by 
the small nuts on the brass rods B. 

The action of the compensation is seen at a 
glance. As the heat lengthens the pendu- 
lum rod and lowers the bob, it also lengthens 
the rods B and raises the ball A to compen- 
sate for the increased length of the pendu- 
lum, and so vice versa. For a seconds pendu- 
lum the ball A may be 2 inches in diameter, 
and the rods B G inches in length. As " com- 
parisons are odious" and provoke controversy, 
the merits of this rod will be alluded to with- 
out comparing them with those of any other. 

1st. It is a remarkably correct timekeeper. 
It has been applied to a great many clocks 
put up in different parts of the country, prin- 
cipally turret clocks, which are exposed to the 
changes of temperature more than any other 
kind of clocks, and has as a general thing 
performed well. The turret clock in the 
Military Academy at West Point, manufac- 
tured by Mr. Byram, of Sag Harbor, has this 
compensation, and during a period of seven 
years its variation frora mean time was not 
over thirty seconds a year for all that time. 

2d. It is the simplest of compensation 
pendulums, and its price is only a little more 
than the wire pendulum to a Yankee clock. 

As every watchmaker wants to have a good 
regulator, and in many cases is only deterred 
by the cost, every little improvement, whether 
it tends to greater excellence or to simplicity 
of construction, must alike be considered a 
step in the right direction. 

B. F. H. 

Sag Haebok, Oct., 1870. 

[We perfectly agree with " B. F. H," in 
regard to the value of wood as a material to 
be used in the construction of a pendulum 
rod for a turret clock, or an ordinary watch- 
maker's regulator, considering it far prefer- 
able to most of the patent compensating 
pendulums that are offered to the trade. We 
have before heard of the rate of running 
claimed for the turret clock at West Point, 
and consider it wonderful, even taking into 
account the fact that it was under the charge 
of scientific men during the entire time.] 



STAKING TOOL. 



Editor Hokological Jouenal : 

I wish to call your attention to my new 
patent staking tool, which is almost indispens- 
able for riveting and unriveting wheels, and 
for rounding and stretching the same. It is 
also one of the most convenient devices for a 
freeing-tool. and for finishing bushings ; also 
for closing pivot-holes, and for removing 
table-roller from balance staffs, and in many 
instances answers the purpose of a lathe in 
connection with the bow, besides being adapt- 
ed to many other purposes that might be 
named. 

Its many advantages will readily be seen 
from the fact that the drill, punch, or finish- 
ing-tool used therewith, have a perfect guide, 
so that a true and unerring blow may be 
given, and the work more accurately per- 
formed than can possibly be done by hand. 

It also forms a true and perfect guide for 
the drill when the bow is used, and also ad- 
mits of many attachments being used there- 
with, such as small anvils and beaks, on which 
many kinds of work maybe done in the most 
accurate manner. 




A represents the block or foundation on 
which the attachments and adjuncts of my 
tool are fixed. It is made of any suitable 
metal, but from experience it has been found 
that cast-iron, steel, brass, or wrought iron 



114 



AMERICAN HOROLOGICAL JOURNAL. 



are most suitable. It is rectangular in form, 
and may be made of any suitable or desired 
dimensions. 

C is a groove, made much deeper than its 
width, running longitudinally from end to end 
of the block A. 

Over this said groove C, and on the top of 
the block A, is closely imbedded a tempered 
cast-steel plate, B, which also runs from end to 
end of the block A, and spans the groove C. 

The surfaces of the block A and steel plate 
B are planed off evenly, and polished, so as 
to form a perfect and true surface. 

The steel plate B is provided with a series 
of holes, graduated in a true longitudinal line 
with the block A, the objects of which are to 
allow the journal of a watch-wheel to pass 
down through them, so that the rim or sides 
of the wheel can be brought flat upon the true 
plain surface of the plate. 

G represents a movable guide, that moves 
or slides from end to end of the block, by 
means of a gib, E, fitted and working closely 
in a dovetail groove, and secured in any de- 
sired position by means of a set-screw, D, all 
these being arranged and located on the side 
of the block A. 

The arm of the guide G leaves the block A 
in a curve, and is brought around over the 
top of the centre of the block, at which point 
the sa : d arm is provided with a perpendicular 
hole or bore, F, which receives a punch, drill, 
or other tool required, as seen at O, which 
represents a drill provided with a grooved 
wheel, designed to be used with the bow. 

This drill is provided with a movable 
sleeve, a, for the purpose of gauging the depth 
of the drill, which is done by moving the 
said sleeve up or down, and securing the 
same in the desired position by means of the 
set- screw, i. 

H shows a cross-bar, with flanges or gibs 
closely fitted over each side of the block A, 
which serves the purpose of a gauge or guide, 
and for steadying the work while being done. 

This cross-bar is rigidly secured in its posi- 
tion by means of a set-screw,/". 

The simplicity of this tool, and the many 
uses to which it is adapted, would readily 
seem to suggest its mode of operation to any 
one of ordinary skill. I will, however, state, 
that to bring the bore or tool to be used 



directly over the centre of any of the holes 
in the block, I have a slim centre punch, 
closely fitting to the bore, which, when the 
set-screw D is slackened, is introduced into 
the hole designed to be used, by which means 
the bore is brought directly over the centre 
where it can be firmly secured by the set- 
screw D. 

Dan. M. Bissell. 
Shelbukne Falls, Mass. 



BENZINE AS A SUBSTITUTE FOR ALCOHOL. 



EDITOK HOROLOGICAL JOURNAL : 

In the 1st Volume of your Journal I read a 
very useful article on "Watch Cleaning," p- 
52. It contains cautions against treating the 
parts of the lever escapement too much with 
alcohol, as the jewels might get loose in their 
shellac fastenings. This makes me wish to 
point out to your readers a cleaning fluid 
which seems little known among the watch- 
makers of your country, viz., benzine. It is a 
stronger dissolvent of all oily or greasy mat- 
ter than alcohol, but does not attack any 
resinous substance, and you may, without the 
slightest fear, leave the escapement for hours 
and days in it without loosening the jewels. 
A few moments of immersion in benzine are 
sufficient for taking away even thick and 
gummy oil, and any one may satisfy himself 
by the simple experiment of throwing a small 
particle of shellac in a bottle with benzine, 
that it does not dissolve in weeks or months- 
It would be most useful if repairers might 
punctually follow the indications given in No. 
2, p. 52, only substituting benzine for alcohol. 
Then many vexations arising from loose jewels 
would be avoided. 

In the same communication I find a state- 
ment leading to the belief that the electro- 
gilding deposited on a coat of ciystallic silver 
is more liable to be brushed off than a gilding 
made in another way. This is not the case, 
for the electro-gilding on a dead silvered 
ground resists brushing just as well as any 
other gilding. This method, compared to the 
old one, allows of making the gold coat almost 
of any thinness, and a great number of Swiss 
manufacturers have taken advantage of this 
possibility for economizing gold, and thus the 



AMERICAN HOROLOGICAL JOURNAL. 



115 



electro-gilding lias been discredited in its 
durability. But if a common-sized watch is 
coated carefully with about ^ dollar's worth of 
gold on a dead silvered ground, it will take 
some hours brushing with a hard brush before 
the silver shines through. 

Saxon. 
o 

TAPS AND MILLS. 



Editok Hokological Joukxal : 

I have a word or two to say in regard to 
fluting very small taps. My method is to 
make them with a conical shoulder, instead 
of a square shoulder, as are those which usu- 
ally accompany finished screws by the gross ; 
in fact, I take the same taps and put them in 
a spring chuck and turn the shoulder back of 
the thread to a conical form, as that insures 
the greatest amount of strength ; then I take 
a common graver and cut a groove from end 
to end of the thread on the tap, sloping the 
point of the graver so as to leave one side 
slightly under-cut in the direction in which 
the tap is to cut ; the other portion of the cut 
will, of course, slope off so as to give the free- 
ing for chips. I make three such cuts equi- 
distant on the circumference, then harden and 
temper. 

In regard to making and tempering small 
pivot drills, I use the best English needles, as 
the steel in those is generally of a superior 
quality. I file the drill a very little smaller 
than the hole which I wish to make in the 
staff or pinion, and then place it in a sloping 
position on any round surface, and then strike 
two or three smart blows with a light bench 
hammer, then cut with a pair of sharp cut- 
ting nippers in the centre of the part so ham- 
mered, and file up to shape. If for very hard 
steel, I give a very small angle to both the 
feeding and cutting angles, about 120° to the 
feeding angles, and 3° or 4° to the cutting 
angles. If the point is somewhat thick after 
this dressing, I rub the flat sides to a point 
crosswise on an oil-stone slip ; I then temper 
by heating to a bright, cherry red, and plunge 
into a piece of white wax, such as dentists use 
for taking impressions, after which I finish 
the cutting edge on the oil-stone ; this will 



make a drill that will cut smoothly and not so 
liable to break in the hole as those that are 
tempered in resin and such materials. For 
large drills I sometimes use resin to harden 
the extreme point, but prefer plain water, 
drawing to a yellow color after hardening. In 
both large and small drills which are used on 
softer metals than steel, I give more of a feed- 
ing angle, say 80° or 90°, but no more than 
3° or 4° of cutting or freeing angle, as all that 
is necessary is to free the body of the drill, 
back of the edge, and it will not have so much 
of a scraping as cutting action. In large 
drills I make a groove directly above the cut- 
ting edge on the face side with a graver or 
fine file, which will make the drill bite in and 
cut faster ; but on the whole, for anything 
larger than the pivot drill I prefer the twist 
drill, as they are always ready. 

A. H. Catbcabt. 
Marshall, Mich. 



PINION MEASUREMENTS. 



Editok Horological Jouknal: 

In several numbers of your valuable monthly 
I have seen directions for obtaining the cor- 
rect measurement of pinions, but none of 
them was based on rule or method, so as to 
be easily remembered when once impressed 
on the mind. The following rule will have 
this advantage, and can be used by any watch- 
maker who is not in possession of the finer 
and more accurate, but costly tools, for all 
practical purposes : Count each tooth and 
space as three until you equal twice the num- 
ber of leaves in the pinion ; this will be the 
diameter of the pinion; set your calipers and 
you have the gauge : Thus : 

A pinion of 5 will require 10 spaces. 



6 


a 


12 


7 


tt 


14 


8 


tt 


16 


9 


tt 


18 


10 


tt 


20 


11 


(i 


22 


12 


tt 


24 



J. E. 



Boston, Oct. 25, 1870. 



116 



AMEKICAN HOEOLOGICAL JOURNAL. 



IMPAIRING ENGLISH WATCHES. 



Editor Hoeological Journal: 

I wish to give a word of advice to your 
young readers. It often occurs with English 
lever watches, especially the larger sizes, 
which have been dropped or roughly used by 
the wearer, that when the watch is taken 
down for repairs, the barrel, great wheel, and 
centre wheel are found running foul of the 
plate, or of each other, and forthwith the 
workman gets his universal lathe to work on 
the plates. Whereas, if the plate pillars, 
which very likely are loose, were firmly rivet- 
ed in the first place, and a little attention 
paid to truing the barrel, the faults would be 
permanently remedied. Another very impor- 
tant point, and one often overlooked, is to 
make sure before putting a watch together, 
that the wheels are quite firm on the pinions. 
I have known many instances of fine English 
and Swiss watches stopping or failing to come 
to time, for no other reason than because the 
scape wheel was loose on the pinion. This 
will sometimes occur in cleaning, especially 
when the wheel is not secured on the pinion 
direct. American watches generally are well 
secured against any such fault. Pinions, too, 
should always be left very clean and smooth; 
every pivot that looks the least bit ragged 
should be burnished, and in no case should the 
workman fail to examine the balance staff 
pivots; see that they are polished, sufficiently 
rounded, and long enough to reach the end 
jewel, with shoulder quite free. The centre 
wheel should have only enough shake to be 
free (having too much is a common fault), not 
only to prevent fouling, but for the better 
working of the dial wheels and hands. Never 
pass an Euglish watch that has been running 
any length of time, without taking the great 
wheel off the fuzee and seeing that the click 
work is in good order, clean, and with fresh 
oil. Never give out a watch unless sure it is 
in beat, if ever so busy, and take pains to 
pin the hair spring in true and flat (if a plain 
one); see that none of the screws in the bal- 
ance are loose or even unscrewed, unless 
intended to be so; pass no bad fitting screws, 
especially important ones, as cock screws, 
barrel plate and bridge screws, and those 
used for seem-in g cap jewels. The improved 



appearance of a watch that has good screws 
will always compensate for attentions given 
in that direction. I use a flat block of lead, 
and a round hammer for riveting pillars. 
The lead holds them sufficiently and prevents 
the ends from spreading. Clackner's barrel 
contractor is a tool that every watchmaker 
should have for truing main-spring barrels of 
all kinds. It saves a deal of time. 

James W. Pembroke. 
Pittsburg, Pa., Oct. 20, 1870. 



FAIR OF THE AMERICAN INSTITUTE OF NEW 
YORK. 



The Twenty-third Exhibition of works of 
industry, applied science and art, in connec- 
tion with this Institute, was opened to the 
public in this city on September 15th, and is 
still in progress, visited by thousands daily. 
Collected within one great building are to be 
seen the choice works of skill, ingenuity, 
handicraft and art, in almost every conceiv- 
able department of industry peculiar to our 
country ; but it is a source of regret to us 
that the Horological Department is not more 
fully represented — only two of the watch 
factories making any exhibition of their pro- 
ducts, and the immense clock interests of the 
country are entirely unrepresented. 

Watches. — The United States Watch Co., 
Marion, N. J. — Giles, Wales & Co., 13 Maiden 
Lane, New York, General Agents — display a 
fine variety of ladies' and gentlemen's 
watches, with full and three-quarter plate 
movements, exposed pallets, straight-line es- 
capements, and stem winders — the Company 
claiming strength and simplicity as the pe- 
culiar feature of the winding mechanism. 
They exhibit over fifty different styles, many 
of them in solid nickel, and beautifully dam- 
askeened. Their style of casing is especially 
worthy of notice, both in design and finish, 
some of them being very elaborately enamel- 
led, and especially adapted for presentation 
purposes. Among the ladies' watches was 
one set with diamonds, valued at $1,800, and 
one valued at $700. They also exhibit a 
number of dials with masonic and other em- 
blems, which were very beautifully executed, 



AMERICAN HOROLOGICAL JOURNAL. 



117 



The New York Watch Co., Springfield, 
Mass., — Messrs. Richard Oliver and Baden, 
No. 11 John Street, New York, General 
Agents — bring forward a goodly display of 
stem-winding and key-winding fine watches, 
complete in gold and silver cases. They also 
exhibit their movements in various stages of 
manufacture ; dials, plain and with sunk sec- 
onds, are seen in 16 different stages ; dial 
plates in 5 ; upper plates in 1 ; balance bridge 
in 6; main-spring band in 7; main-spring in 2; 
winding arbor in 6 ; centre wheel and pin- 
ion in 11 ; 2d wheel and pinion in 11 ; 3d 
wheel and pinion in 11 ; 'scape wheel and 
pinion in 11 ; pallets and lever, in a multipli- 
city of different stages, and compensation 
balances in 12 ; hair-springs in 4 ; balance 
roller and staff in 12 ; regulators in 7 ; wind- 
ing and setting arbor cups in 10 ; ratchet, 
click, and spring in 14 ; male and female 
stops in 9 ; and motion wheels, screws, and 
jewels, in many different processes of manu- 
facture. The escapements of these watches 
resemble very closely the one used by Jur- 
genaen, and in the arrangement of the move- 
ment simplicity predominates; nothing useless 
is introduced, and they somewhat resemble 
the superior class of Swiss movements. Sev- 
eral of the movements are in nickel, beauti- 
fully damaskeened in various patterns. 

Howard and Co., of Broadway, exhibit a 
very fine case of watches, the production of 
the American Watch Co., but not for compe- 
tition, and also a fine display of gold and 
silver chains. 

Clocks. — This department is very meagrely 
represented, and contains nothing of special 
merit. Jame3 Rodgers, of Liberty street, New 
York, exhibits a showy clock and case, design- 
ed to be fastened up on a wall, probably in 
some large office or hall. Chas. E. Market, 792 
Third avenue, New York, a boy 16 years of 
age, exhibits a little clock all made by himself 
at his leisure hours. The clock is covered with 
glas3, and of course the works are exposed, 
and with boyish simplicity he has two roses 
on the top of the movement, and a small bird 
flying between the two, keeping time with the 
pendulum. The whole is creditably executed, 
and we hope that it will be an incentive to 
the young man towards higher efforts, and an 
example to all our New York, and in fact all 



our American watchmakers' apprentices, to 
spend a portion of then' leisure hours in such 
studies. 

L. Thorne, Robinson street, New York, ex- 
hibits a globe clock. We have not had an 
opportunity of having it explained to us, or 
of examining the principle of its construction, 
and we can only say that it is a small clock 
under a glass shade, evidently designed to 
show certain astronomical movements. J. 
Cohen, 942 Third avenue, exhibits a clock for 
a watchmaker's or jeweller's window. A clock 
of similar construction is described at page 
202 of the first volume of this Journal. 

William H. McNary, Brooklyn, exhibits a 
clock having no hands. The hours, minutes, 
and seconds are marked on the edges of re- 
volving cylinders, and the figures show 
through small holes in the dial plate. Mr. 
McNary claims, and not without some show 
of reason, that his system is less liable to mis- 
takes in reading the time than the system < f 
hands pointing to figures, and its simplicity 
enables any child that knows figures to tell 
what o'clock it is. We have examined the 
system by which the cylinders are made re- 
volve, no friction springs are used to keep 
them steady, and consequently to drag on the 
clock ; they are arranged perfectly free, and 
can only move at the proper time. We hope 
Mx\ McNary will, in a short time, make his 
system more public. 

Mr. William H. Horton, Jersey City, N. J., 
exhibits an adjustable compensation pendu- 
lum, or rather he styles it an adjustable com- 
pensating regulator, of which Messrs. Terhune 
& Edwards, 18 Cortlandt street, New York, 
are agents. This is one of the many modi- 
fications of Ellicott's pendulum, and the in- 
ventor makes the rather extravagant claim 
" that it is superior in every respect to any 
pendulum in use ; that it in perfect, etc." As 
a scientific Journal, we are always ready to 
acknowledge merit, and assist in its develop- 
ment, but we are opposed to all charlatan 
ism, and unhesitatingly denounce the distin- 
guishing feature of this pendulum to be a 
delusion ; and the general workmanship, 
both in the important fittings, and that 
which tends to make a good general appear- 
ance, to be the very worst in any part of th2 
section it belongs to. We may have occasion 



118 



AMERICAN HOROLOGICAL JOURNAL. 



to refer to this pendulum in some forthcoming 
number, and at present can only remark, 
that no stronger argument is required for 
the necessity of a purely horological journal, 
than the fact of this pendulum being placed 
for competition in an exhibition of the Ameri- 
can Institute. 

Astronomical and Optical Instruments. — 
Blunt & Co., 179 Water street, New York, 
make a fine display of the principal instru- 
ments they manufacture, and the only ones 
of the kind on exhibition. Conspicuous in 
their case stands a fine transit theodolite. 
This comprehensive instrument will measure 
horizontal and vertical angles reading on 
both circles to 10 seconds of arc, and com- 
pass angles can also be measured by it. The 
axis is perforated for illumination of the cross 
wires, and having both erect and diagonal 
eye pieces and astronomical reticule, can be 
i.sed for celestial observations. The diplei- 
doscope or meridian instrument they exhibit 
is a very useful and convenient little instru- 
ment, and contains all the accuracy requisite 
for ordinary purposes. We are informed that 
Professor B. H. Bull, of the New York Uni- 
versity, used one of them in the country dur- 
ing the past summer, and his observations 
with the dipleidoscope never differed more 
than a very few seconds from the observa- 
tions taken with his fine transit erected in the 
upper part of this city. 

T. H. McAllister, 49 Nassau street, New 
York, exhibits a fine selection of microscopes 
and microscopic apparatus, and three con- 
densing lenses, and a variety of other articles 
which appear to be first-class goods, and are 
tastefully arranged. Miller Brothers, 69 Nas- 
sau street, New York, also show microscopes 
and microscopic apparatus and a variety of 
lenses. The professional microscope in this 
case is very fine. 

Solid Silver and Plated Goods. — The Ex- 
hibition is rich in this department. Tiffany 
and Co., 550 and 552 Broadway, New York, 
exhibit a magnificent selection of solid silver 
presentation plate. The Queen's Challenge 
Cup, won by the yacht " America," of the 
New York Yacht Club, in 1851, and lately 
coi tested for by the English yacht " Cambria," 
and still remaining in possession of the New 
York Yacht Club, is exhibited in their show- 



case ; also the plate "presented to the New 
York Club by Commodore James Ashbury, 
owner of the " Cambria," and which was won 
by the " Magic ;" also a number of other 
cups won in yachting contests, — all of the most 
gorgeous description. We . consider the ar- 
tistic skill and talent of the country in this 
branch of the business to be concentrated in 
the goods shown by Messrs. Tiffany & Co. 

Reed & Barton, Taunton, Mass., display a 
fine variety of silver, and silver-plated goods, 
of elegant and artistic design. Their show- 
case is very attractive. 

Simpson, Hall, Miller & Co., Wallingford, 
Conn. — Office, 19 John street, New York — ex- 
hibit a case of fine silver-plated ware. Elegance 
and durability are claimed by the exhibitors 
for their goods. 

The Lippiatt Silver Plate and Engraving 
Co., 10 Maiden Lane, New York — Manufac- 
tory at Newark, N. J. — make a fine display of 
their goods, engraved and chased by their 
patented steam machinery. These goods are 
artistic in design, and the pearl satin finish 
is well executed. 

Miscellaneous Articles. — L. L. Smith, 6 
Howard street, New York, exhibits a number 
of miscellaneous articles to show the useful- 
ness and practicability of nickel plating. A 
ship's binnacle and a steam engine are among 
the articles exhibited. 

The Bradsley Nickel and Manufacturing 
Co., 71 & 76 Fulton street, Brooklyn, also ex- 
hibit specimens of their nickle plating. 

M. Bourdon, No. 6 Old Slip, N. Y, exhibits 
the superiority of Emil Prevost's new liquid 
chromic acid as a substitute for other liquids 
in galvanic batteries. The liquid chromis 
acid is suitable for any description of battery, 
and recommends itself on the scox'e of superior 
strength, economy, durability, and evenness 
of action, and has no odor whatever. 

Messrs. L. L. Whitlock & Co., Office 708 
Broadway, N. Y, P. O. Box 6775, exhibit one 
of Whitlock's drop presses for hand or me- 
chanical power, but is especially valuable to 
jewelry manufacturers who use hand power. 
It can be worked five times as fast as the 
common hand drop, and takes but from one- 
quarter to one-sixth the power to do so. Mr. 
Whitlock informs us that he has another drop 
press nearly completed, which he expects will 



AMERICAN HOEOLOGICAL JOURNAL. 



119 



strike a blow equal to one hundred pounds 
once every minute or oftener, and when once 
started might be worked by a lady as easily 
as a sewing machine. Mr. Whitlock lays no 
claim to making or creating power ; he simply 
sa ves and stores up the little forces as they ac- 
cumulate, which is the secret of the results he 
attains in the extra amount of work done by 
his machines. We noticed a choice and costly 
selection of Swiss drawing instruments and 
materials, exhibited by Keuffel & Esser, 116 
Fulton street, and also by J. H. Queen, 5 Dey 
street, andanassortmentof American drawing 
instruments by Benoit & Wood, 142 Fulton 
street, Xew York, completes the list of articles 
likely to be interesting to our readers. In 
conclusion, we would make a suggestion to our 
young friends to emulate Chas. E. Market, 
and show some little production of their skill 
at the next Exhibition of the Institute. It 
need not be an entire watch or clock ; proba- 
bly a very few have the facilities to make a 
whole instrument, but all could exhibit some 
feats of skill in handling the file, polishing a 
flat surface, using the lathe, and many other 
difficult manipulations. Doubtless the Insti- 
tute vould give facilities for the exhibition 
of such articles, which would be a means of 
developing powers that otherwise may be 
dormant and probably never see light. 



ANSWERS TO CORRESPONDENTS. 



A. H. C, Marshall, Mich. — The thing you 
have to do with your lathe is to fix in or on 
your swing rest a live mandrel, as described 
on page 118 of the .Journal. You will not 
need the swinging ftame, as there described, 
because your rest itself is the swing, and can 
be made to approach the centre of your 
lathe mandrel by its screw. The only diffi- 
calty will be in connecting it by a counter 
shaft with your lathe pulley in such a man- 
ner as to allow the necessary amount of 
swing to your rest which carries the grinding 
and po'ishing mandrel. 

We arranged something of the kind for an 
American lathe, which may give you an idea 
how to adapt something to your lathe. On 
the bed of the lathe M we fixed a rest N, to 
which was attached a swing frame A, carry- 



ing a short mandrel and pulley, on the pro- 
jecting end of which we fixed the cutting and 
polishing disks c, which could be made to 
approach the lathe centre B, by means of the 
screw P. The difficulty was to run a band 




from tiie centre shaft to carry the poiismng 
arbor, and yet allow the swinging movement 
without altering the tension of the band. 
This we did by placing beyond the counter 
shaft an upright arm X, carrying a pulley Y, 
at the top and hinged at the bottom to allow 
of a swinging motion to correspond with the 
swing of the frame carrying the grinding 
disks ; the band was carried completely 
around the large pulley E on the centre shaft 
and thence around the little pulley on the 
arm, which was kept at the proper tension by 
a spring Gr, sufficiently strong ; this arrange- 
ment, of course, allowed full motion to the 
swing frame without altering the length of 
the band. 

J. B. M., Toledo, 0.— One of the earliest es- 
capements applied to stationary time-pieces 
after the discovery of the pendulum was the 
anchor, so called from its resemblance to the 
flukes of an anchor. It is not positively 
known who invented it ; some attribute the 
invention to Thomas Mudge, some to Clement 
It was claimed as a dead beat, " because the 
curves upon which the beats were made are 
arcs of circles of which the anchor pivot is 
the centre," and was so regarded for more 
than eighty years, or until Berthoud, in 1763, 
" gave minute rules by which the anchor es- 
capement invented by Clement, a London 
clockmaker, in 1861, might be made recoiling 
for small clocks, with the view of rendering 
the vibrations isochronal " All authority 
seems to confirm the opinion that it was 
dead beat, and the name seems to have more 
reference to the motion (as seen) of the sec- 
onds hand, that to any sound it gave ; the 



123 



AMERICAN HOROLQGICAL JOURNAL. 



hand always in such escapements remains 
motionless, or dead, till the moment of es- 
caping, just the opposite of the recoil escape- 
ment, which was always on the move — rest- 
lessly alive. In the endless descriptions of 
escapements extant, by common consent, all 
such as permit excursions of the pendulum 
beyond the impulse plane, without disturb- 
ance of the condition of rest in the escape 
wheels, are called dead beat ; no matter what 
their peculiarity of construction, or by what 
additional name called, if they possess the 
property above mentioned they are undoubt- 
edly dead beat escapements. 

D. B. M., Texas. — We have recently seen 

in a foreign scientific and industrial journal 

a method described of covering iron or steel 

with copper, which will, perhaps, be just the 

thing you require for coating the articles you 

mention. " First make the article entirely 

bright by fill, scratch brush, or any of the 

usual modes. Apply to the surface a coating 

of cream of tartar, then sprinkle the surface 

with a saturated solution of sulphate of 

copper, and rub with a hard brush." The 

coating of copper deposited on the iron is 

said to be very even and durable. 

E. L.D., Ohio. — You cannot make a new hole 
in the inner end of a clock spring without 
straightening out the spring and recoiling it, 
which is very difficult to do unless you have a 
clock spring reel. " The game is not worth 
the powder," when springs can be bought so 
cheaply. 

M. O., Pa. — The word Horology is derived 
from the Latin, Horologium, a description of 
the hours. Tne French give us Horloge ; the 
Italians, Ora ; the Germans, %\\\K, and the 
Greek, u-poXoytov. 

AMERICAN HOROLOGICAL JOURNAL, 

PUBLISHED MONTHLY BY 

G-- B. MILLER, 

229 Broadway, N. Y., 
At $'2.59 per Year, payable in advance. 

A limited number of Advertisements connected 
with the Trade, and from reliable Houses, xvill be 
received. 

&§■= Mr. J. Herrmann, 21 Northampton 
Square, E. C, London, is our authorized Agent 
for Great Britain. 

All communications should be addressed, 
G. B. MILLER, 
P. 0. Box 6715, New York. 



"EQUATION OF TIME TABLE. 

GREENWICH MEAN TIME. 

For November, 1870. 



ii 




Sidereal 
Time 


Equation 






Sidereal 


& 




of 


of 


Equation 


Din*, 
for 
One 


Time 


o 


Day 


the Ssmi- 


Time to be 


of 


or 




of 


diameter ! Subtracted 


Time to be 


Right ' 


o 


ilon. 


Passing 


from 


Added to 


Ascensioa ' 


t*> 




the 


Apparent 


Mean Time. "■""■ 


of 


R 




Meridian. 


Time. 




Mean Sun. 






s. 


M s. 


M. S. S. 


h. ir. f. 


Tn. 


1 


66.95 


16 17.20 


16 17.22 i 0.056 


14 42 17.01 


W. 


2 


67 07 


16 18.16 


16 18.17 ; 0.024 


14 46 13.57 


Th. 


3 


67.19 


16 18.33 


16 18.32 ! 0.009 


14 50 10.12 


Fri. 


4 


67.31 


16 17.69 


16 17.68 i 0.043 


14 54 6.68 


Rat 


5 


67.42 


16 16.24 


16 16 22 | 0.077 


14 58 3.23 


Sh. 


6 


67 54 


16 13 98 


16 13.95 0.111 


15 1 59.79 


M.. 


7 


67.66 i 16 10.88 


16 10.84 0.146 


15 5 56.34 


Tn. 


8 


67.78 16 6.95 


16 6.91 0.181 


15 9 52.90 


W. 


9 


67.90 i 16 2.17 


16 2 11 


0.216 


15 13 49.45 


Th. 10 


68.02 ! 15 56.55 


15 56.48 


0.252 


15 17 46.01 


Fri. 11 


68 14 15 50.07 


15 49.S9 


d.288 


15 21 42.56 


Sat 


12 


68 26 15 42.73 


15 42.65 


0.324 


15 25 39.12 


Sn. 


13 


68 38 


15 34.52 


15 34 43 


0.360 


15 29 35.67 


M.. 


11 


68.50 


15 25.45 


15 25 35 


0.396 | 15 33 32.23 


Tu. 


15 


68.61 


15 15.51 


15 15 40 


0.432 15 37 28.79 


W. 


16 


68 . 73 


15 4.71 


15 4.59 


0.467 


15 41 25.34 


Th. 


17 


68.84 


14 53.06 


14 52.94 


0.503 


15 45 21.90 


Fri 


18 


68.96 


14 40 55 


14 40.42 


0.538 


15 49 18.45 


Sat 


19 


69.07 


14 27.20 


14 27 06 


0.573 


15 53 15.01 


Sn. 


20 


69.19 


14 13.01 


14 12.87 


0.608 


15 57 11.57 


i\r.. 


21 


69.30 


13 58.00 


13 57.85 


642 


16 1 8.12 


Tn. 


22 


69.41 


13 42.18 


13 42.03 


0.676 


16 5 4.68 


W. 


23 


69 52 ' 13 25.56 


13 25.40 


0.708 


16 9 1.23 


Th. 


24 


69.62 


13 8.17 


13 8.00 


0.740 


16 12 57.79 


Fri. 


25 


69.73 


12 50.01 


12 49.84 


0.771 


16 10 54.35 


Sat 


26 


69.83 


12 31.11 


12 30.91 


0.802 


16 20 50.91 


Su. 


27 


69.93 


12 11.49 


12 11.32 


0.832 


16 24 47.46 


M.. 


28 


70.03 


11 51 17 


11 51.00 


0.861 


16 28 44.02 


Tn. 


29 


70.13 


11 30 16 


11 29.99 


0.889 


16 32 40.58 


W. 


30 


70.22 


11 8 49 


11 8 32 


0.916 


16 36 37.13 



Mean time of the Semidiameler passing may bo found by sub- 
tracting 0. 19 s. from the sidereal time. 

The Semidiametor for mean neon may be assumed the same as 
that for apparent noon. 

PHASES OF THE MOON. 

D. H. M. 

© Full Moon 7 19 31.9 

i Last Quarter 15 20 58.9 

@ New Moon 22 13 20 9 

) First Quarter 29 10 33.0 

D. II. 

( Apogee 8 1.5 

C Perigee .... 22 48 



Latitude of Harvard Observatory . . . 



42 22 48.1 



Long. Harvard Observatory 4 44 29 . 05 

New York City Hall 4 56 0.15 

Savannah Exchange 5 24 20 572 

Hudson, Ohio 5 25 43.20 



Cincinnati Observatory . 


5 37 


58.062 


Poin 




8 1 


42.64 




APPARENT 


APPARENT 


MERID. 




R. ASCENSION. 


DECLINATION. 


PASSAGE. 




D. H. M. S. 


o ' a 


H. M. 




1 13 52 35.43.. 






Jupiter. . . . 


1 5 42 25.07.. 


.. + 22 50 13.3.. 


...14 57.5 


Saturn . . . 


1 17 39 36.48.. 


..+22 27 11.2.. 


..2 56.9 



AMERICAN 




0102:1c 





You. II. 



NEW YORK, DECEMBER, 1870, 



No. G. 



CONTENTS. 

Heat 121 

SoFr Solder 125 

construction of the addendum of a train wheel 

Tooth bt Co-ordinates, 126 

Adjustments to Positions, Etc., 129 

Engraving, 133 

Hair-Spring Gauge 134 

Transit Instruments, 134 

Worn Rims 135 

Light, ■ 135 

Answers to Correspondents, 140 

Equation of Time Table, 144 



* * * Address aU communications for Horological 
Journal to G. B. Miller, P. 0. Box 6715, New York 
City. Publication Office 229 Broadway, Boom 19. 



HEAT. 



NUMBER FITE. 



EXPANSION OF SOLIDS CUBICAL EXPANSION LIN- 
EAR EXPANSION CONSTRUCTION OF PYROM- 
ETERS — EXPANSION OF LIQUIDS EXPANSION OF 

AERIFoRM FLUIDS, ETC. 

In the present number the relation between 
the temperature and the volume of a sub- 



stance will be considered. In some cases it 
is the increase of the volume of a body which 
we wish to estimate, while in others, as for 
instance when we are considering a sub- 
stance such as a bar, of which the length is 
the important element, it is change of length 
and not change of volume with which we con- 
cern ourselves. The former of these is cal- 
led linear, and the latter cubical expansion. 
To determine the cubical expansion of a solid 
we may either, first, weigh the substance at 
different temperatures in a liquid of which 
the absolute expansion is known, or we may, 
secondly, enclose it in a glass vessel, the re- 
mainder of which is filled with mercury or 
water ; and if the absolute expansion of 
either of these liquids is known, that of the 
glass envelope and of the enclosed solid may 
be easily determined by mathematical calcu- 
lation. 

We present a table showing the dif- 
ference between the linear and the cubical 
expansion of six of the principal metals, and 
give the names of the observers. 





Mean linear expan- 


Mean cubical expan- 




Substance 


sion between 32° 


sion between 32* 


Observers. 




and 212" Fahr. 


and 212' Fahr. 






.0 10837 


.00254 


Lavoisier & Laplace, Roy & Ramsden, Dulong & Petit, Renault 


Copper 


.001716 


.005127 


" " Daniell " Kopp . 




.002882 


.0089 


" " " Kopp. 


Tin 


.001959 


.0069 


(< 11 (1 u 


Zinc 


.002976 


.0089 


Daniell " 




.0012U4 


.003546 


Lavoisier & Laplace, Borda, Dulong and Petit. 



From this it will be seen that the cubical ex- 
pansion is in every case equal to about three 
times the linear expansion of the same sub- 
stance. The reason of this relationship be- 
tween the two follows at once from the fact 
that when an uncrystallized solid expands, it 
does so in such a manner that its figure at 
one temperature is similar to that at another. 
Universal experience demonstrates the truth 
of this statement, and it can be very easily 
shown that, assuming it to be correct, the 



cubical expansion of a substance will then 
be as nearly as possible three times as great 
as its linear expansion. 

Several methods of finding the linear ex- 
pansion of solids have been proposed and 
adopted by experimentalists. The most com- 
mon, although probably not the most accu- 
rate form is, to place the metal to be operated 
upon in a horizontal position, a few inches 
above a table, one end of the metal rigidly 
attached to a pillar firmly fixed in one end of 



122 



AMERICAN EOROLOGICAL JOURNAL. 



the table, and the other end of the metal fitting 
freely into a support fixed at a convenient dis- 
tance from the first. When heat is applied to 
the metal its loose end presses against the 
short arm of a lever whose long arm forms a 
pointer, which exhibits, by its movements 
along a graduated circle, any change of 
length in the metal. Thus, were the metal 
to expand, the pointer would be pushed up- 
wards ; and were it to contract, the pointer 
would fall downwards ; and any change in 
the length of the metal is thus rendered vis- 
ible exactly in the same manner as watch- 
makei's measure the size of a piece of work 
on the quadrants constructed for the par- 
pose. 

Another plan which admits of great accu- 
racy, and is known as Lavoisier's method, is 
to place an axis in a horizontal position on 
the top of two pillars, such as are used for 
a transit in a permanent observatory. A 
stout bar is rigidly fixed to this axis, and 
hangs between the pillars, and is attached to 
the metal to be operated upon. One end of 
the axis projects be3 T ond one of the pillars, 
and carries a telescope pointing to a vertical 
scale of inches placed at a considerable dis- 
tance. The action of this instrument will be 
seen at a glance. When the metal under 
trial expands or contracts in length, the bar 
hanging between the pillars will be moved ; 
consequently the telescope will be moved 
also, and indicate the different divisions on 
the vertical scale it is pointing to. 

Other most elaborate instruments have been 
devised for this purpose, but the principles 
upon which they are founded are either the 
same as the two already mentioned, or a com- 
bination of them both. Wedgewood's py- 
rometer is an instrument for measuring very 
high temperatures, and its action depends on 
the contraction which takes place in baked 
clay when heated. An air thermometer, how- 
ever, furnishes a much more accurate means 
of obtaining the same result, and Breguet's 
Metallic Thermometer may also be used with 
great advantage. In some forms of the py- 
rometer the metal that is being experimented 
upon is placed in a trough or bath filled with 
water, and the heat communicated to it by 
heating the water. 

Tae following table of the linear expansion 



of solids, has been lately arranged by Pro- 
fessor Balfour Stewart, LL.D. F.R.S., and 
Superintendent of the Observatory at Kew, 
England, and exhibits the results obtained by 
various pyrometers. It is instructive to notice 
sometimes the coincidence between the deter- 
mination of different observers, and some- 
times the difference between those of the 
same observer when operating upon different 
specimens of the same substance. 

We suppose that by means of the methods 
already described a great amount of accuracy 
of measurement may be obtained, yet there 
is an uncertainty regarding the real tempera- 
ture of the experimental bar, and this becomes 
very great for temperatures above the boiling 
point of water. In such cases, where a bath 
is used, it is not only very difficult to keep 
this at a constant temperature, but it is also 
very difficult to estimate accurately the tem- 
perature by means of a thermometer. This 
uncertainty with regard to estimation applies 
still more strongly to higher temperatures ; 
but for the range between freezing and boil- 
ing water, which is that of the foregoing table, 
it may perhaps be assumed that the deter- 
minations are very good. Whence, then, 
proceed the differences between the results of 
different observers, and even between those of 
the same obssrver when estimating the ex- 
pansion of different specimens of the same 
substance. This is probably due to two 
causes. In the first place, substances which 
bear the same name are not always of the 
same chemical composition. Of these, gk ss 
may be mentioned as a prominent example ; 
and accordingly we find the expansion of this 
substance ranging in the table from .000918 
to .000776. Brass, cast-iron, and steel are 
likewise compounds of which the composition 
is variable. But besides this, the commercial 
varieties of those substances which, when 
pure, are elementary, such as iron, leid, silver, 
gold, etc., often contain a very appreciable 
amount of impurity, so that the composition 
of different specimens is by no means uniform. 

Very often, too, a comparatively small im- 
purity causes a very great alteration in some 
of the properties of a metal. In the next 
place it ought to be observed that two solids 
may have precisely the same chemical com- 
position, while yet their molecular condition 



AMERICAN HOROLOGICAL JOURNAL. 



123 



inay be different, owing to a difference in the 
treatment which they have received. Thus 
steel, heated and suddenly cooled, is a very 
different substance from steel which has not 
been treated in this manner ; and accordingly 
we find that while steel tempered yellow has 
for its expansion .0001240, untempered steel 



has .0010S0. Glass, also, will behave in a 
different manner, according as it is annealed 
or unannealed ; and in certain cases it is al- 
most impossible to obtain two bars, although 
made of precisely the same material, which 
shall, in all their properties be precisely 
alike. 



Name of Substance. • 


Length at 212° Fhr. of 

a rod whose length at Name of Observer. 
32° = 1.000000. 




1.000876 
1.000898 
1.000918 
1 000812 
1.000872 
1.000776 
1.000808 
1.000861 
1.001722 
1.001712 
1.001716 
4 001867 
1 001890 
1.001855 
1.001893 
1 001220 
1.001235 
1.001182 
1.001156 
1.001079 
1 001080 
1.001240 
1.001145 
1 001109 
1.001072 
1.002848 
1.002788 
1.001938 
1 002173 
1.001767 
1.001910 
1.001909 
1.001951 
1 001466 
1 001552 
1 001514 
1.001230 
1.000884 
1.000857 
1.002976 


Lavoisier and Laplace. 






ii 1 1 


Glass English flint 


ii tt 


" tube 


ii it 
Roy and Ramsden. 






Dulong and Petit. 
Lavoisier and Laplace. 

tl It 












Lavoisier and Laplace. 
Roy and Ramsden. 

tt tt 

Lavoisier and Laplace. 




" (English plate in a rod five feet long. . . 






Dulong and Petit. 






Lavoisier and Laplace. 
ii ii 




ii it 




Roy and Ramsden. 
ii it 




it 


Daniell. 




Lavoisier and Laplace. 
Daniell. 

Lavoisier and Laplace. 

it it 


Tin (Kast Indies) 


" (Falmouth) 




Daniell. 

Lavoisier and Laplace. 
it tt 

Daniell. 

Lavoisier and Laplace. 

ti it 

tt ii 


ii 






Dulong and Petit. 




Zinc 









The expansion of metals by heat, and their 
subsequent contraction, are often employed 
with great advantage in the arts, and fre- 
quently as most efficient mechanical powers. 
The amount of force which produces these 
expansions and contractions is enormous, 
being equal to the mechanical power required 
to stretch or compress the solids in which 
they take place, to the same amount. On 
heating an iron sphere of 12| inches diameter, 
from 32° to 212° Fahr., the expansion exerts 
a force of 60,000 lbs. upon every square inch 
of its surface, or 30,000,000 lbs. upon the 
whole sphere. A bar of iron one square 
inch in section is stretched Ttrhra part of its 



length by a ton weight; the same elongation, 
and an equal amount of force, is exerted by 
increasing its temperature 16° Fahr. In a 
range of temperature from winter to summer 
of 80° a wrought-iron bar 10 inches long will 
vary in length t-oVo- oi " an inch, and will exert 
a pressure, if its two ends be fastened, of 50 
tons upon the square inch. 

The immense force of expansion is clearly 
proved in many notable instances in large 
works of engineering where iron is largely 
used as a material of construction. The 
Southwark Bridge, over the Thames, at Lon- 
don, is constructed of iron, and surmounted 
by stone, and the arcs rise and fall one inch 



124 



AMEKICAN HOROLOGICAL JOURNAL. 



within the usual range of atmospheric tem- 
perature. The Hungerford Chain Suspension 
Bridge, also over the Thames, has a span of 
1,352 feet in length ; the height of this chain 
roadway varies in the hottest day in summer 
and the coldest day in winter to the extent of 
eight inches. 

The Menai Suspension Bridge weighs 
20,000 tons, and this is raised and lowered 
14 inches by the change of temperature be- 
tween winter and summer. The Victoria 
Bridge, at Montreal, is exposed to great vicis- 
situdes of heat and cold, and it is found that 
beams of iron, 200 feet in length, are subject 
to a movement of three inches in the climate 
of Canada. It would be a curious and in- 
structive calculation for some of our young 
friends to determine how many pounds less 
of telegraph wire, or the number of tons less 
of railroad iron, is required to stretch across 
this Continent in winter than is required in 
summer. 

Aeriform fluids are greatly expanded by 
heat, and much more than either solids or 
liquids, for the same increase of temperature 
With equal increase of heat they all expand 
equally. If, therefore, the ratio of expansion 
for one gas, as oxygen, be known, then the 
ratio for common air and for all other gases 
will be known also. The ratio of expansion 
for all gases has been found to be about ^-^j 
of the volume which the gas possessed at 32° 
for every degree of Fahrenheit's thermometer. 
This calculation is based upon the experi- 
ments of Gay Lussac, who found that 1,000 
cubic inches of atmospheric air raised from 
the freezing point to the boiling point, were ex- 
panded so as to make 1,375 cubic inches. It 
follows, therefore that one cubic inch of at- 
mospheric air at 32° will, if raised to 212°, 
be expanded to 1.375 cubic inches, and for 
everj' additional 180° it will receive a like in- 
crease of volume. The ratio of expansion 
being ? i^ for 1°, if any volume of air at 32° 
be raised to the temperature of 32° -)-490 o = 
522°, it will expand to twice its volume; and 
if it be raised to a temperature of 32° -f- 
(2° X 490°)= 1,012°, it will be expanded to 
three times its volume, and so on. Later 
experiments have slightly altered this ratio, 
and show that the different gases do not all 
expand to exactly the same degree for equal 



increase of heat ; the inequality may how- 
ever be disregarded for all practical purposes. 
In general the gases and vapors all dilate 
equally, and to the same degree as atmos- 
pheric air. 

It is a striking fact, that water at certain 
temperatures does not obey the usual law of 
expansion from heat, and contraction from 
cold. Between 32° and 40°, if water be 
heated it contracts ; if it be cooled it expands. 
If therefore water at the temperature of 60° 
be cooled, it will contract till it reaches 40° ; 
and then, if it be cooled to a lower degree 
than this, it will expand. At 40°, therefore, 
water is said to possess its maximum density. 
At the moment of congelation water also un- 
dergoes a still further expansion ; and this 
takes place with irresistible power, so that 
the vessels in which it is confined, if they be 
full are infallibly broken. This is the cause 
of the bursting of water-pipes at the ap- 
proach of winter. This expansion is suppos- 
ed to be due to the crystallization of the wat- 
er as it freezes, and to the fact that the crys- 
tals which are formed do not lie side by side 
closely packed together, but cross each other 
at angles of 60° and 120°, thus leaving large 
interstices, and the water therefore necessa- 
rily occupies more space than it did before. 
The force with which this expansion takes 
place is very great, and cannon filled with 
water and plugged at the muzzle, may readily 
be burst. In 1784-5 Major Williams, at Que- 
bec, made some experiments upon this sub- 
ject, in one of which an iron plug three 
pounds in weight was projected from a bomb- 
shell to the distance of 415 feet, and shells 
one and a half and two inches in thickness 
were burst by freezing of the water. The 
Florentine Academicians burst a hollow brass 
globe having a cavity of only an inch, by 
freezing the water with which it was filled ; 
and it has been estimated that the expansive 
power in this case was equal to 27,720 pounds. 
Water is not the only liquid wmich expands 
as it solidifies. The same effect has been ob- 
served in a few others, which assume a high- 
jy crystalline structure on becoming solid. 
Melted antimony, bismuth, iron, and zinc, are 
examples of it. (Mercury is a remarkable 
instance of the reverse, for when it freezes it 
surfers a very great contraction.) It is on 



AMEBICAN HOKOLOGICAL JOTIKNAL. 



121 



account of this property that fine castings 
can be made from iron. The metal, as it 
cools and solidifies, expands so as to force 
into the most delicate lines of the mould. 
Antimony possesses this property in a high 
degree, and for this reason is mixed with tin 
and lead to form type metal, and give the 
mixture the property of expanding into the 
moulds in which the types are cast. It is be- 
cause gold and silver do not possess this 
property, but on the contrary shrink greatly 
as they cool in the moulds, that coins cannot 
be made by casting, but require to be 
stamped. 

Liquids expand more for a given increase 
of heat than so ids. Alcohol, on being heated 
from 32° to 212°, increases in bulk -^ ; olive 
oil r \f ; water -^g-. Twenty gal'on? of alcohol 
measured in January will become twenty-one 
in July. The cubical expansion of a liquid 
may be either real or apparent. By apparent 
expansion is meant the apparent increase of 
volume of a liquid confined in a vessel which 
expands, but in a less degree than the liquid 
which it contains. By real or absolute ex- 
pansion is meant the true change of volume 
of the liquid without reference to the contain- 
ing vessel. One of the various methods em- 
ployed for this purpose is to fill the bulb of a 
thermometer, of which the internal volume or 
capacity is supposed to be known, at the 
various temperatures of observation. This 
bulb is attached to a graduated stem, and the 
internal capacity of each division of this stem 
is likewise supposed to be known. When 
this instrument has been filled with the liquid 
under examination it is exposed to different 
temperatures, and for each of these the posi- 
tion which the extremity of the liquid occu- 
pies in the stem is accurately noted. It is 
clear that by this means the volume of the 
liquid for each temperature becomes known, 
and hence the amount of its real expansion 
may be easily deduced. 



J^ST" It is with sincere regret that we learn, 
through Mr. Geo. E. Wilkin, of Syracuse, of 
the death of the wife of Mr. Moisritz Gross- 
mann, after a long and painful illness of many 
months. Mr. Grossmann has many admirers 
in this country who will sympathize with him 
in his affliction. 



SOFT SOLDEB. 

It is often very convenient, and, in fact, 
sometimes necessary, to have soft solder 
which will flow at different degrees of tem- 
perature. Many instances occur in which 
jobs cannot (in the country) be done by a 
professional jeweller, consequently the watch- 
maker is expected to do whatever nobody else 
can ; and he must often run the risk of spoil- 
ing work by subjecting it to too intense a 
heat; whereas, if he had a little easy-flowing 
soft solder, there would be no danger. 

From the following table you can easily 
prepare such as you wish — if only a little of 
some of the sorts; it will be found conveni- 
ent : 

1 part Tin, 25 Lead— melts at 580° F. 



No. 



9. 
10. 
11. 

12. 6 

13. 4 
14 
15. 
16. 
17. 
18. 



10 


" 


" " 541 


5 


" 


" " 511 


3 


" 


" " 482 


2 


it 


" " 441 


1 


" 


.< « 370 


1 


" 


" " 334 


1 


" 


" " 340 


1 




" " 356 


1 


<< 


" " 365 


1 


" 


« ,< 378 


1 


" 


" " 381 


4 


" 1 pt. 


Bism'th 320 


3 


" 1 " 


" 310 


2 


"1 " 


" 292 


1 


"1 " 


" 254 


2 


"2 " 


" 236 


3 


"3 " 


" 202 



No. 8 is the common tinsmith solder. No. 
7 is the most fusible, unless bismuth be ad- 
ded. No. 18 will melt at 122°, by the addition 
of 3 parts of mercury. The most convenient 
form for using soft solder is to have it in 
wire. It is very easy to have it in that form; 
for when you have it melted in a ladle, in 
pouring it out on a flat iron or stone you 
must trail it — that is, draw your ladle along 
so as to flow out on the stone a thread of 
metal. With a little practice you cannot but 
succeed. Any of these alloys will flow with 
the ordinary soldering fluid. 

Another convenience for soft soldering is 
not as much used as it might be, and would 
save injury to many a job; that is, a soldering 
iron, the same as a tinsmith's, only minu'er. 
A piece of copper wire, an inch long and one- 
fourth inch thick, filed away almost to a 
point, with a wire handle about 4 inches long, 



126 



AMERICAN HOROLOGICAL JOURNAL. 



terminated by a bit of wood or cork. In 
using, heat the copper in the lamp flame by 
laying - it across something, to save time, and 
when hot enough to melt the solder, touch 
the end into your pickle, which will brighten 
it; then touch it to a bit of solder, and it will 
instantly take it up. Then you can apply it 
at any point you wish, without heating the 
balance of the article in hand. 



CONSTRUCTION OF THE ADDENDUM OF A 
TRAIN WHEEL TOOTH BY CO-ORDINATES. 



The formation of the curves of the adden- 
dum of a train wheel tooth by sections of the 
epicycloid is attended with considerable diffi- 
culty. In order to get a tooth large enough 
to form a complete curve, by the ordinary 
method of mechanical drawings, the space 
required for the radi? of the primitive and 
generating circles passes much beyond the 
limits of the general appliances. Hence it 
follows that there is a great obstacle in the 
way of many horologists for getting a knowl- 
edge of the properties of an epicycloidal tooth. 

This difficulty is surmounted by the method 
of coordinates, by which a tooth of any mag- 
nitude is easily constructed, without the ne- 
cessity of drawing the primitive or generating 
circle. A reference to Fig. 1 will explain the 
basis of this method.* 

Let a b and a 1 b 1 represent the tooth of a 
wheel of 60 teeth, terminated at the pitch 
circle rn m ' . Let A be the centre of the prim- 
itive or pitch circle (i. e., centre of the wheel), 
A a its radius; and let n be the centre of the 
generating circle, and n a its radius, propor- 
tioned to the radius of a pinion of 6 leaves, 
and here representing one leaf in line with 
the line of centres n A. By a revolution of 
the pitch circle of 6° the radius n a will ro- 
tite through an angle of 60°, and n 3 will 
then be the position of the centre of the gen- 
erating circle, and n 3 a- the position of the 
face of the adjacent leaf ; here again in line 
of centres n 3 A. With the centre of genera- 
ting circle in n, o is a point in the arc o l co- 
inciding with a. With the centre in n l , this 



* The diagrams cannot make any pretence to ac- 
curacy, and are only given to illustrate the method 
set forth. 



point o lies in the arc o o 2 ; with the centre in 
n 2 it lies in arc o o 3 , and with the centre in 
n 3 it lies in arc o o 4 , its radius forming, with 
the radius of the pitch circle, the angles on 1 
A, o n 2 A and o w 3 A — these being respect- 
ively 20°, 40° and 60°. The generating point 
o has therefore a triple motion, viz. : it re- 
volves about A, rotates about n, and radiates 
from A. 

The measurement of these motions of the 
generating point o enables us to determine 
so many points in the curve as are deemed 
essential in their relation to fixed points and 
lines, which lines are called coordinates. 

Let a a 1 , y 3 y 4 , Fig. 2, represent the section 
of sector equal to the angular measure of a 
tooth and terminated by the pitch circle and 
the extremity of the addendum; a a 1 will then 
equal the width of a tooth measured at the 
pitch circle, which is taken equal in magni- 
tude to the space; then by finding the mag- 
nitude of the parallels, the points o, as the 
points of intersection, can be determined, and 
the joining of these points will form the epi- 
cycloidal addendum. 

Proportions and Definitions for a Drawing. 
— Make a a 1 =12; bisect it and draw the per- 
pendicular m n = 12.212. Draw the paral- 
lel y 3 y 4 , and make n y 3 and n y* each =6.3; 
therefore y 3 y* = 12.6; join y 3 a and y* a 1 . 
Draw perpendiculars to a y 3 and a y*, from 
o and x ; then determine 15 points in the 
curve a o o o, as follows : Measure off on the 
lines a x and a 1 x — 

1 = 0022 

2= 0144 

3 = 0467 

4 = 1038 

5 = 2122 

6 = 3720 

7= 5662 

8= 8613 

9= 1.2215 

10= 1.6655 

11 = 2 2029 

12= 2 8404 

13= 3.5827 

14 = , 4.4421 

15 = 5.4235 

On the lines ay 3 and a 1 y* measure off — 

1 = 0610 

2= 2451 

3= 5402 

4= 9714 



AMERICAN HOROLOGICAL JOURNAL. 



127 





128 



AMEKICAN HOKOLOGICAL JOUBNAL. 



5 = 1.5153 

6== 2.1689 

7 = 2.9314 

8= 3.7927 

9= 4.7623 

10= 5.8187 

11 = 6.9600 

12 = 8.1791 

13= 9.4663 

14 = 10.8156 

15= 12.2160 

Draw parallels from the points measured 
off, as indicated in Fig. 2, join the points of 
their intersection and the curves are com- 
plete. 

The following formulas will give the coor- 
dinates : 

Let a = the radius of the primitive circle 
= to radius of a wheel of 60 teeth; b — the 
radius of generating circle, = to radius of 
pinion of 6 leaves ; c = the line of the circle, 
d= / o A n 3 (Fig. 1); then (Fig. 1) point o 

x = sin (6°-d) (sec d. c-cos 60°6) 
y = ^cos (6°— d) (sec. d. c-cos. 60°6)~) - a 

Observation. — The pract ; cal construction of 
a perfect epicycloidal tooth by an engine with 
a curved cutter, which is formed artificially, 
cannot be demonstrated. My limited knowl- 
edge of the wheel cutting engines used in 
United States watch factories, leads me to 
suppose that they are of this description. 
While such is the case, no definite calibre in 
the pitckings, and vice versa, is reliable. I am 
prepared to say that engines can be con- 
structed which will cut an epicycloidal tooth 
to mathematical accuracy. The line of cen- 
tres will then be determined by gauging the 
wheel, and vice versa, instead of using the 
depthing tool, which is an engine of destruc- 
tion in the hands of unskilled workmen. 

J. Hermann. 
21 Northampton Square, 
London, Oct. 10, 1870. 

[There can be no doubt that the subject of 
the proper curves of the acting faces of the 
teeth and leaves of wheels and pinions, con- 
sidered not merely from a theoretical point 
of view, but in the reduction of scientific 
theories to actual practice, demands the 
closest investigation on the part of all me- 
chanicians, whether watchmakers or mill- 
wrights, who construct gearing of any de- 



cription. And although it may not always 
be possible to impart to wheels and pinions, 
with mathematical precision, those curves 
that in theory produce the least possible fric- 
tion, and consequently the greatest economy 
of motive power and the minimum of wear, 
still the mechanic who aims at the best re- 
sults should, even with limited appliances, 
endeavor, at any rate, to approximate to that 
which is scientific, and if he can be guided in 
his practice by his eye only, in shaping or se- 
lecting wheels and pinions, then it is impor- 
tant he should be able to draw on paper the 
proper form for the teeth and leaves of 
wheels and pinions of any numbers, that he 
may thereby educate his eye to a knowledge 
of the requisite epicycloidal curve. Any 
gross departure in practice from the true 
theory in this respect will, in horology, oven 
though every thing else be of the highest order 
of excellence, produce poor time-keeping, 
thus defeating the primary object of a time- 
keeper ; in the application of the rack and 
pinion movement, it will cause an unpleasant 
jerking and rubbing sensation, and ultimate 
destruction of the parts ; and in cam move- 
ments, such as the lifting of mill stamps, the 
valve rods of marine engines, and kindred 
appliances, a heavy jarring, caused by an im- 
proper relation between the velocity of the 
acting part of the cam and the inertia of the 
corresponding lifted body, is full of ruin to 
costly machinery at every stroke. We men- 
tion these two last movements because the 
principles that govern their construction are 
analogous to those of the wheel and pinion. 

We are sure our readers will not accuse us 
of any desire of disparaging their intelligence 
if we remark that the publication of the fore- 
going scientific elucidation of a method of 
delineating the epicycloidal curve of a wheel 
tooth, which has been kindly furnished to us by 
the talented teacher of drawing in the British 
Horological Institute, will be shooting over 
the heads of a great number, who would be 
far more interested in some article giving a 
short cut to success in the repairing line, 
which is all well enough in its place ; but, on 
the other hand, we are consoled by the reflec- 
tion that the list of our readers includes the 
names of many who thirst after knowledge, 
and to such we take an especial pleasure in 



AMERICAN HOROLOGICAL JOURNAL. 



123 



introducing the above-mentioned author and I 

i 
his subject. 

Referring to the " Observation " in the j 
closing part of the article, we may say that! 
we quite agree with Mr. Hermann when he 
says the curve of the tooth of any watch 
wheel cannot be demonstrated to be epicy- 
cloidal, even though it be such. Still, the 
attempt is made, at least in our watch facto- 
ries, to produce that curve, and, it is claimed, 
with success. Whether the pitchings are re- 
liable, and the depths on the whole are good, 
can be tested by actual experiment in a 
depthing tool, but if the general satisfaction 
with which the American watches are re- 
garded, by both wearers and repairers, is any 
indication of success in the application of 
sound principles, then it must be conceded 
that any errors and inaccuracies they may 
possess, as a class, are not more than are 
incidental to the manufacture of such minute 
work by machinery. We hope Mr. Hermann 
will give our readers the benefit of his views 
on the construction of an engine for cutting 
" an epicycloidal tooth to mathematical ac- 
curacy." — Ed.] 



ADJUSTMENTS TO POSITIONS, ISOCHKONISJi 
AND COMPENSATION. 



NUMBEB TWO. 



We have, in the first number, on the subject 
of adjustment to position, endeavored to 
show that it can be accomplished on the prin- 
ciple of presenting equal surfaces of the 
pivots of the balance to friction ; for, if equal 
surfaces touch equal surfaces in all positions 
during the oscillation of the balance, the fric- 
tion must be equal in all positions ; and, if 
the friction is in all positions the same, the 
arcs of vibrations of the balance will also be 
the same in ail positions ; and since equal 
arcs of vibrations are performed in equal 
time, the watch will in all positions run 
alike. 

Now, directly from the above reasoning we 
infer, that if the arcs of vibrations are un- 
equal in different positions, the friction must 
be unequal ; and we are therefore enabled to 
determine inequality of fiiction, by observing 



the arcs of vibrations ; and since we know 
that the lesser friction produces the greater 
arcs of vibration we also know in which posi- 
tion to remedy the inequality in the friction. 
We have thus bi-iefly stated our reasoning, 
for the purpose of contrasting it with the 
method generally adopted among watch- 
makers to determine unequal friction, which 
consists of observing the running of the 
watch, and then altering the condition of the 
pivots according to the difference of the time 
it indicates in different positions during the 
same number of hours, and on the theory 
that the watch will go faster under the influ- 
ence of less friction, and slower when the 
friction is greater. But we may ask the ques- 
tion, why will it go faster with less f iction, 
and slower with more ? If we admit that 
there is such a thing as a principle of isoch- 
ronism in the hair-spring under certain con- 
ditions, which would cause arcs of vibrations 
of unequal extent to be performed in the 
same time, we could not infer that the advo- 
cates of this theory supposed such a spring to 
be in the watch, for, as we have just said, we 
know that less friction produces greater arcs 
of vibration. But they say less friction makes 
the watch go faster ; and if such a hair-spring 
is not supposed to be in the watch, our ques- 
tion is equally unanswerable, for our experi- 
ence teaches us that, according as circum- 
stances are, greater arcs of vibration may be 
performed either slower or faster. The fact 
is, that, as to adjustment to position, the 
faster or slower running of a watch proves 
nothing. 

But we think we have sufficiently indicated 
the means of adjusting to position, and will 
therefore proceed to investigate the next 
adjustment — that of isochronit-m. We have 
promised in our last to furnish a translation 
of Prof. Phillips's theory, and we know of no 
better authority on the subj< ct ; but as his 
reasoning is of the very highest order, and 
the subject necessarily a troublesome one, 
since the essentially complex form of the 
hair-spring introduces into the application of 
the theory of the elasticity some of the most 
complicated differential equations, it will be 
difficult for those who are not acquainted with 
mathematical logic, to follow it throughout ; 
nevertheless it is to be hoped that those who 



130 



AMEKICAN HOKOLOGICAL JOUBNAL. 



feel a real interest in the subject will be en- 
couraged by the value of it, to study them- 
selves those sciences in order to be able to 
understand it. It would be difficult to write 
into plain English all the demonstrations in 
the higher calculus and trigonometry, but we 
will endeavor to give such hints, as will never- 
theless convey the result of the reasoning to 
the minds of those who will follow it atten- 
tively, although they may not understand the 
process. 

The theory of the isochronism of a cylin- 
drical as well as of a flat hair-spring is here 
based upon the principle that, during the vi- 
brations of the balance, as well as when it is 
at rest, the centre of the coils — considering 
them as circles drawn around the axis of the 
balance — shall always coincide with the cen- 
tre of the axis of the balance, and that there- 
fore this shall also be, during arcs of what- 
ever extent of the vibrations of the balance, 
the centre of gravity of the hair-spring. This 
he proves can be accomplished by certain 
terminal curves of the hair-spring, to find 
which, is the main object of the treatise. He 
looks upon the question as a mechanical 
problem, of which the following is the sub- 
stanco : " A hair-spring being attached to a 
balance, to find the laws of their common 
movement." In practice we have evidently 
to take into account secondary details, such 
as the influence of the oil, friction, etc ; 
nevertheless the solution and rules which 
shall be developed satisfy the problem as ab- 
solutely as the theory of the pendulum does 
in its application to the measurement of time. 
He first solves the problem of the equilibrium 
of the system of the hair-spring and the bal- 
ance, which we shall now give in his own 
words, cautioning the reader to keep well in 
mind the signs used to express certain quan- 
tities. 

The hair-spring and the balance being in 
their natural position of equilibrium, we sup- 
pose the balance to be made to describe an 
angle of rotation, a, and we ask what is the 
amount of coupling necessary to maintain it 
in this new position against the action of the 
handspring ? 

In order to solve this problem, we arrange 
the system under two co-ordinate rectangular 
axes passing through the centre O of the bal- 



ance, and one of which also passes through 




that extremity of the hair-spring which 
is fastened. If we consider, in this new 
position of equilibrium, the balance and 
hair-spring as forming one solid, the system 
must be in equilibrium under the action of 
the coupling applied to the balance, the 
amount of which, G-, is precisely what we 
wish to determine. Moreover, the centre of 
the balance being stationary, nothing can 
hinder it from being considered free, pro- 
vided we apply at the point O a force equal 
and contrary to the pressure which it exerts 
against the sides of the hole. Let us desig- 
nate by Y and X the components, according 
to O Y and X, of the force thus applied at 
the point O, which point we shall then con- 
sider free. B being the position occupied by 
any point of the hair-spring in the new state 
of equilibrium, we call x and y its co-ordi- 
nates ; S the length of the hah'-spring, com- 
prised between that point and the end of the 
hair-spring fastened ; L the total length of 
the hair-spring ; M its amount of elasticity ; 
finally, p the radius of the curve of the hair- 
spring at the point B, in the new position of 
equilibrium, and p the radius of the curve 
at the same point B, in the natural state 
of the hair-spring, when the amount G is 
null. 

In the new state of equilibrium this would 
not be disturbed if we solidified the entire 
portion of the hair-spring comprised between 
the point B and the extremity engaged in the 
balance, and we would then have to consider 
the equilibrium of a solid formed of this por- 
tion of the hair-spring together with the bal- 
ance, and subjected on one part to the coup- 
ling G, which acts upon the balance, and to 
the forces X and Y, on the other hand, to the 
molecular actions exercised on the section B 
by the non-solidified portion of the hair- 
spring. If we transpose to the point B the 



AMERICAN HOROLOGICAL JOURNAL. 



131 



forces X and T, as also the coupling G, the 
resulting coupling must hold in equili- 
brium the molecular action developed by 
the non-solidified portion of the spring. 
Or, if in order to fix our ideas, we suppose 
that the angle of rotation a be in such a 
direction that the radius of the curve shall 
have diminished at the point B, the amount 
of molecular action is equal to 

and we shall have 

( 1) Mfi--) = G + Yz-Xt/. 

This equation is applicable to all points of 
the hair-spring. 

AVe can, therefore, multiply the two mem- 
bers by ds and integrate for the entire extent 
of the hair- spring, which will give : 

Let us first occupy ourselves with the 
second member, we have 



and 



fds = L 



Gfds = GJj 

Next, if we call x l and y x the coordinates 
of the centre of gravity of the hair-spring, it 
is evident that 

fxds = 'Lxi aQ d fy <2s = L y l ; 

consequently 

Yfx ds = YLa-j andXy* 1 yds = XLy l 

TTe pass now to the first member of the equa- 

d s 
tion (2). We see that — is, for the natural 

form of the hair-spring, the angle formed by 
two consecutive normals, and consequently 

/d s 
— is nothing else than th^ angle com- 
prised between the two normal extremes. In 

/d s 
— is the angle between two 

normal extremes in the new form of the 
hair-spring ; but where this has passed from 
the first position to the second, the normal, 
relative to the extremity fastened, remains 
invariable in direction, because it is fastened 
at this point. On the other hand, since the 
other extremity of the spring is fastened in the 
collet of the balance at an angle with the 
circle of the collet, which remains also con- 



stant because of its being fastened, the result 
is, that in passing from the natural position 
of the ha^r-spring to the new position of equi- 
librium, the normal of the spring, at its ex- 
tremity corresponding to the balance, turns 
by an angle a. 

It follows from what precedes that we have 
simply : 

/— _ C ds — 
p J Pa 

and equation (2) becomes 

M a = G L + L (Ysb, - Xy t ). 
Let us admit, for the present, that the term 
L (Y x l —~X.y 1 ), which is in the second mem- 
ber, be null or negligible — this point will be 
fully treated, a little further on, in all that 
concerns it, and the necessary conditions 
established to prove sufficiently that it is so— 
then the equation (3) will be reduced to 

M « = G L 
or, 



(4) 



G = 



Ma 



which expression is very simple, and shows 
that the amount of the power of the coupling 
tending to move the balance is proportional 
to the angle which the latter has described 
after leaving the natural position of equi- 
librium, and which, moreover, gives the 
amount of this coupling expressed in function 
of the amount of elasticity and length of the 
hair-spring. 

Henceforth it is easy to find the time of the 
oscillations of the balance. In effect, if we 
call A the amount of inertia of the balance, 
with respect to its axis of rotation, we have, 
in every instance, observing that the power 
G acis as a rtsistanct : 

A d — °--G 
A dt*~ ^ 

or, on account of (4) 

d 



(5) 






M, 
dl 2 ~ L 

I designate by a , the angle of motion of 
the balance which answers to the limit of the 
oscillation when its swiftness is null, and we 
have, by multiplying the two members of (5) 
by 'Ida and integrating : 



(6) A d^ = T;K- a )" 



This expression shows that the angular 
swiftness of the balance -^j is indefinitely 



132 



AMERICAN HOROLOGICAL JOURNAL. 



null when a = a or when a= — a , so that, 
if it were not for divers passive resistances, 
it would always vibrate to the same extent to 
each side from its position of equilibrium. 
We draw from equation (6) 



(7) 



/al 



It is now time to integrate this equation for 
all the values from a— — a Q to a=.a . 
Now 



/, 



d 






|^-C-J 



= arc sin — + constant 



then 



/ 



-"a -/" 



and consequently by designating by T the 
time of an oscillation, equation (7) gives : 



(8) 



T = 



' / — 
V M 



which simple relation gives the time of the 
oscillations, and they will be found isochronal 
whatever may be their extent. The preced- 
ing expression (8) is analogous to that which 
gives the time of the smaller oscillations of 
the pendulum. We see that the length I of 
the simple pendulum, which would perform 
its oscillations in the same time as the balance, 
would be expressed in the formula 



(9) 



'-*¥■ 



As to the further conditions of isochronism, 
let us take up equation (3) again, in which 
we have neglected the term L Y#, — X^), 
and examine under what conditions we can 
effectively consider it of no value, on which 
will depend definitively the isochronism of 
the oscillations and the accuracy of formula 
(8). 

In the first instance this term would al- 
ways be null if x and y were constantly equal 
to zero, that is to say, if the centre of gravity 
of the hair-spring coincided always with the 
centre of the axis of the balance. From this 
we infer dii ectly that it is important to give 
to the coils of the hair-spring a sensibly cir- 
cular form and concentric to the staff, so that 
the centre of gravity of the entire spring be 
on the staff and deviate from it as little as 
possible during its motion. 

In the second instance, the term L 



(Yx 1 — Xy 1 ) would vanish yet if the compon- 
ents X and Y were null, and consequently if 
the pressure of the staff were always null, or 
if this pressure were always at the centre of 
gravity of the hair-spring. In fact, in prac- 
tice this pressure is always null in well-made 
time-pieces, since — provided the oil has not 
been neglected — we cannot find the slightest 
wear of the pivots or their holes, even after 
many years of running. Nevertheless, we 
will examine, under all the developments 
which the subject shall bring forth, the con- 
ditions under which we can rigorously and 
mathematically attain to this end. We shall 
then see, as a consequence of this analysis, 
that if, for the flat hair-spring, we can arrive 
at it but for small oscillations of the balance, on 
the contrary, for the cylindrical ones we will 
obtain this result for the greatest as well as 
for the smallest of vibrations, and that by 
means of particular theoretical terminal 
curves and a total length of the spring, which 
is to be neither too long, nor above all too 
short. 

To this effect we mention, that if X and Y 
are null or can be entirely neglected, equation 
(1) gives : 



I-!— — 

P Po~ M ' 3 



XL" 



or because of (4) 

(io) »-!_■. 

K P Po L 

It follows from this, that then the tension 
of the curves is uniform. Thus, if p is con- 
stant p will be the same, i. e., if the coils have 
the form of the circumferences of circles in 
their natural state, they will be yet, after their 
deformation, circumferences of circles, though 
of a different radius. 

Reciprocally to what precedes, if we had 
always, for all points of the hair-spring 

— - ~ =t' i- e -> tne difference; — — constant, 

P Po -Li P Po ' 

equation (1) shows that we would then forci- 
bly have Y = o and X = o, and that conse- 
quently equation (4) with its consequences 
would take place. 

We shall, in subsequent numbers, continue 
to give a digest together with liberal literal 
translations from the work of M. Phillips, 
trusting the readers of the Horological 
Journal may be benefited thereby. 

Horologist. 



AMERICAN HOROLOGICAL JOURNAL. 



133 



EXGRAVISG. 



In the first volume of the Hokological 
Joukxal, was an article on the subject of En- 
graving, which treated of the process of 
Etching, and gave an explanation of the 
geometric lathe, by which dies are engraved, 
with combinations of lines forming geometric 
figures. "We propose to continue the subject 
of engraving, and will speak of the work 
which is done by the hand. Almost all en- 
gravings are produced by etching, combined 
with lines made by the hand. The lines made 
with the graver without the use of acid, are 
technically called " dry pointed." 

For engraving on steel and copper, a few 
tools only are necessary. First are the etch- 
ing points, of which one or two only are nec- 
essary. Second, gravers, two or three of 
which are required, which may be lozenge 
shaped or square. A scraper and a burnisher 
are also required. 

The etching points are used to trace 
lines through the varnish on the plate, for 
the action of the acid. They are also 
used to make light lines on the plate, when 
acid is not to be employed. The gravers 
are used to cut deep and broad lines. 
The scraper is used to remove any burr of 
metal raised by the graver in cutting. Also 
in the kind of engraving called mezzotint, the 
different shades of tint are scraped out by 
this tool. The burnisher is used to make the 
bright lights in mezzotint engraving, and to 
remove accidental scratches on plates, and in 
line engravings to erase lines that have been 
cut too deep. 

In mezzotint engravings the plates are pre- 
pared by rolling over them in every direction, 
a small wheel with sharp points, which cov- 
ers the plates entirely with minute dots, and 
if printed from, would present a black sur- 
face. 

"When thus prepared the design is traced 
upon the surface, and the engraver takes the 
scraper, and scrapes to greater or less depth, 
according to the tint required. In the high- 
est lights the burnisher is used, as aforesaid. 
The effects produced by the mezzotint pro- 
cess are very soft. There are no lines, and 
the different tints shade into each other, with 
delicate gradations ; and this process is also 



employed in connection with line engravings, 
with happy results. 

" Stippling " is a term employed to denote 
effects produced by series of dots. "When 
used alone, the gradations of shade are made 
almost imperceptibly. In all work indica- 
ting softness and delicacy, stippling may be 
employed to advantage. In most represen- 
tations of statuary stippling is used alone, 
the absence of lines giving an impression of 
the surface of the marble. With line engrav- 
ing stippling is also much used. In most 
pictures in which human figures are repre- 
sented the flesh-tints are produced by stip- 
pling, sometimes alone, and sometimes com- 
bined with delicate lines. Line engraving 
consists of series of lines side by side, of 
greater or less depth according to the color 
required. "When series of lines cross other 
series of lines, the term cross-hatching is 
used. It may be observed here that the lines 
are cut into the metal ; and to print, the ink is 
filled into the lines, the surface of the plate 
being made entirely clean. The plates are 
then passed under heavy rollers, and an im- 
pression is made on paper upon the press. 
In former times copper was the principal 
material used for plates, but, as a limited 
number of impressions could only be made, 
steel was substituted for copper. It is harder 
to cut than copper, but is so much more dur- 
able that it is generally employed, especially 
for bank notes. And recently an invention 
has been made by which copper plates, after 
being engraved, may be faced with steel, thus 
increasing their durability. 

The introduction and use of steel plates 
may be claimed as American. About a 
quarter of a century ago, Jacob Perkins in- 
vented a method of hardening steel after it 
was engraved. By bank-note establishments 
this method is extensively employed to obtain 
duplicates of designs. A design is engraved 
with the finest skill and beauty ; rollers of 
softened steel are prepared and passed over 
this finely engraved plate, receiving a sharp 
impression in relief. These rollers are then 
hardened, and are dies, from which may be 
made as many impressions as are required. 
A large steel plate is softened and a number 
of impressions are made from the die on it. 
It is then hardened and ready for printing. 



134 



AMEEICAN HOBOLOGICAL JOURNAL. 



To digress a little, we will state that the bank 
notes of the United States are the finest in 
u ;e in the world. The present bank of Eng- 
land notes are printed from an electrotype 
surface, and an indifferent quality of paper. 

The notes of the Bank of France are also 
printed from an electrotype surface, though 
in a much neater and more elegant manner 
than the Bank of England. 

Bank notes require vignette or picture 
engraving, letter engraving, and geometric 
engraving by machines. The pictures or vig- 
nettes are usually executed in lines ; stippling 
and mezzotint not being sufficiently durable. 

It is customary for engravers to confine 
themselves to special departments of art. An 
engraver of pictures rarely cuts letters ; and 
a letter engraver seldom can engrave pic- 
tures. There is also much work that comes 
within the province of the letter engraver ; 
scroll-work and other ornamental designs are 
within the scope of this department. Here- 
tofore we have been speaking of engravings 
from which impressions are made. But the 
letter engraver finds a large field for the exer- 
cise of his talents in engraving uptn plate 
and jewelry. All lettering is done on silver 
and gold, in the same manner as on copper 
or steel. In another paper, we will take up 
this department of the art, including orna- 
mentation and enchasing:. 



— o- 



HAIR-SP1UNG GAUGE. 



Editor Horological Journal : 

Noticing in the October number of the 
Journal, your answer to A. S. M., of Mass., I 
write you respecting a gauge for hair-springs, 
which I find the most convenient and best 
adapted to the wants of the watch repairer, of 
any tool I have seen for this purpose. I have 
used Bottom's hair-spring gauge for several 
years, until I found this instrument. I re- 
fer to the Micrometer, illustrated on page 
No. 329, Horological Journal. The instru- 
ment I use is a Swiss-made tool, somewhat 
different in construction from your illustra- 
tion, but, in principle, identical. It cost 
$6.50 or $7.00. I find it a perfect tool for 
measuring pivots, hair-springs, or any small 
article of which it is desirable to know the 



exact dimensions. Jewel holes can also be 
measured by putting a round broach into the 
hole, and measuring the broach. In measur- 
ing hair-springs, both the width and thick- 
ness can be got, the same as in gauging main- 
springs by Dennison's gauge. It can proba- 
bly be purchased of any tool and material 
dealer in New York; and it is worth much 
more than its price to any watch repairer 
who wishes to do work with precision. 

I have no doubt that by a series of meas- 
urements, carefully conducted, a table may be 
formed of sizes of springs, weight of bal- 
ances, and numbers of vibrations, by which 
any repairer may know to a certainty the size 
of hair-spring required, when the other con- 
ditions are found. E. E. Eawson. 

Barton, Vt. 



TRANSIT INSTRUMENTS. 



Editor Horological Journal : 

Among the letters we have received this 
month expressing the satisfaction with which 
the writers have used our Patent Improved 
Transits, were the following, which are a fair 
sample of general approval. We enclose 
them for publication, believing your readers 
will be interested in testimony confirming the 
reputation of these instruments for absolute 

accuracy. 

Helena, Montana Territory, 

Nov. 10th, 1870. 
Messrs. John Bliss & Co. : 

Gentlemen, — In relation to the Transit In- 
strument purchased of you last spring, I am 
pleased to state that during the past thirty 
years I have depended on my own observa - 
tions for the purpose of keeping correct time 
in which period I have been familiar with 
nearly all kinds of instruments used for like 
purpose, and I have never used any with 
en-eater ease and satisfaction than your watch- 
maker's transit. Under your printed instruc- 
tions, at my first attempt I placed in proper 
position, and recent verifications determine 
its constant accuracy. This mode of observa- 
tion is made easy by the application of your 
splendidly finished and constructed prism ; 
magnifying the field of view with such dis- 
tinctness enables the operator to mark the 



AMEKICAN HOROLOGICAL JOURNAL. 



135 



meridian line to the fraction of a second. I 
must say I like the instrument very much. It 
is ornamental in the show-cas'-e, easy to use, 
and as correct as the most costly instrument. 
I "would not change it for any other time- 
taking instrument, and without hesitation 
I recommend it, particularly for "watchmakers' 
use. Yours truly, 

Charles Kumlet, 
Watchmaker and Jeweller. 

Ashtabula, Ohio, Nov. 12th, 1870. 
Messrs. John Bliss & Co.: 

Gentlemen, — If the Transit could not be 
bought for less than twice the money I paid 
for it, I would not be without it, after even 
the short acquaintance I have had. I enclose 
for your inspection my last observation, taken 
alone. Respectfully yours, 

Geo. "W. Dickinson. 

Salem, Mass., Nov. 5th, 1870. 
Messrs. John Bliss & Co. : 

Gentlemen, — After a thorough test of the 
Transit Instrument I bought of you in Oct., 
1868, I find it all you represented it to be — if 
anything, beyond my expectations. I would 
most cheerfully recommend it to all in want 
of such. Yours truly, 

W. H.Kehew. 



WORN RIMS. 



EDITOB HOEOI.OGICAL JoUKNAIil 

It is a great annoyance to watch-wearers 
to have the rim of hunting cases so worn by 
the friction of the springs that they will not 
close tight, or perhaps not stay closed at all. 
This trouble can be frequently remedied by 
undercutting the rim at such an angle that 
the spring will draw the case tight. I have 
always found it difficult to do this neatly with 
a graver, or other hand tool. I now use, for 
this purpose, the ordinary steel ratchet wheel, 
taken from the material box, mounted on the 
lathe as a cutting burr. A wheel should be 
selected with very fine teeth; and if not hard, 
it should be hardened, the same as any other 
cutting tool, and mounted on the live spindle 
in the most convenient manner. 

This burr will cut and finish a square hole in 
a main-spring so narrow as to be difficult to 



punch, besides saving the risk of breaking 
small files in finishing the hole; the spring 
to be cut should be bent backwards, so that 
the hole will not be cut too long. It will also 
cut solder from the grooves in spectacles af- 
ter mending, and do a hundred other little 
things that no file will do. 

I noticed some time since, in your paper, 
an item about the use of the potato for pro- 
tecting stones, enamel, chasing, and engra- 
ving from the effects of heat, in hard soldering. 
That was the process taught me in my ap- 
prenticeship, and that I followed until lately; 
then I heard of another way, which is cleaner, 
and absolutely sure to effect the object, if 
carefully done : The part to be protected 
should be well covered with a thick paste of 
whiting and water. 

This may be new to some, as it was to me 
a year ago, and will prove to all who try it a 
valuable process. B. F. H. 

Sao Harbor, L. I. 



LIGHT. 



In reply to numerous inquiries and sugges- 
tions in regard to this subject, we perhaps 
cannot do our readers a greater kindness, 
than to lay before them the remarks of Mr. 
John Tyndall, of London. 

general considerations — rectilinear propaga- 
tion OF LIGHT. 

The ancients supposed light to be pro- 
duced and vision excited by something emit- 
ted from the eye. The moderns hold vision 
to be excited by something that strikes the 
eye from without. What that something is 
we shall consider more closely subsequently. 

Luminous bodies are independent sources 
of light. They generate it and emit it, and do 
not receive their light from other bodies. The 
sun, a star, a candle-flame, are examples. 

Illuminated bodies are such as receive the 
light by which they are seen from luminous 
bodies. A house, a tree, a man, are exam- 
ples. Such bodies scatter in all directions the 
light which they receive ; this light reaches 
the eye, and through its action the illuminated 
bodies are rendered visible. 

All illuminated bodies scatter or reflect 
light, and they are distinguished from each 



136 



AMERICAN HOROLOGICAL JOURNAL. 



other by the excess or defect of light which 
they send to the eye. A white cloud in a 
dark-blue firmament is distinguished by its 
excess of light ; a dark pine-tree projected 
against the same cloud is distinguished 
through its defect of light. 

Look at any print of a visible object. The 
light comes from that point in straight lines 
to the eye. The lines of light, or rays, as they 
are called, that reach the pupil furru a cone, 
with the pupil for a base, and with the point 
for an apex. The point is always seen at the 
place where the rays which form the surface 
of this cone intersect each other, or, as we 
shall learn immediately, where they seem to 
intersect each other. 

Light, it has just been said, moves in 
straight lines ; you see a luminous object by 
means of the rays which it sends to the eye, 
but you cannot see round a corner. A small 
obstacle that intercepts the view of a visible 
point is always in the straight line between 
the eye and the point. In a dark room let a 
small hole be made in a window shutter, an 
let the sun shine through the hole. A 
narrow luminous beam will mark its course 
on the dust of the room, and the track of the 
beam will be perfectly straight. 

Imagine the aperture to diminish in size 
until the beam passing through it and mark- 
ing itself upon the dust of the room shall 
dwindle to a mere line in thickness. In this 
condition the beam is what we call a ray of 
light. 

FORMATION OF IMAGES THROUGH SMALL APERTURES. 

Instead of permitting the direct sunlight to 
enter the room by the small aperture, let the 
light from some body illuminated by the 
sun — a tree, a house, a man, for example — be 
permitted to enter. Let this light be received 
upon a white screen placed in the dark room. 
Every visible point of the object sends a 
straight ray of light through the aperture. 
The ray carries with it the color of the point 
from which it issues, and imprints that color 
upon the screen. The sum total of the rays 
falling thus upon the screen produces an 
inverted image of the object. The image is 
inverted because the rays cross each other at 
the aperture. 

Experimental Illustration. — Place a lighted 
candle in a small camera with a small orifice 



in one of its sides, or a large one covered by 
tinfoil. Prick the tinfoil with a needle ; the 
inverted image of the flame will immediately 
appear upon a screen placed to receive it. By 
approaching the camera to the screen, or the 
screen to the camera, the size of the image is 
diminished ; by augmenting the distance 
between them, the size of the image is 
increased. 

The boundary of the image is formed by 
drawing 1 from every point of the outline of the 
object straight lines through the aperture, 
and producing these lines until they cut the 
screen. This could not be the case if the 
straight lines and the light rays were not 
coincident. 

Some bodies have the power of permitting 
light to pass freely through them ; they are 
transparent bodies. Others have the power of 
rapidly quenching the light that enters them ; 
they are opaque bodies. There is no such 
thing as perfect transparency or perfect 
opacity. The purest glass and crystal quench 
some rays ; the most opaque metal, if thin 
enough, permits some rays to pass through 
it. The redness of the London sun in smoky 
weather is due to the partial transparency of 
soot for the red light. Pure water at great 
depths is blue ; it quenches more or less the 
red rays. Ice when seen in large masses in 
the glaciers of the Alps is blue also. 

SHADOWS. 

As a consequence of the rectilinear motion 
of light, opaque bodies cast shadows. If the 
source of light be a point, the shadow is 
sharply defined ; if the source be a luminous 
surface, the perfect shadow is fringed by an 
imperfect shadow called a penumbra. 

When light emanates irom a point, the 
shadow of a sphere placed in the light is a 
divergent cone sharply defined. 

When light emanates from a luminous 
globe, the perfect shadow of a sphere equal to 
the globe in size will be a cylinder ; it will be 
bordered by a penumbra. 

If the luminous sphere be the larger of the 
two, the perfect shadow will be a convergent 
cone ; it will be surrounded by a penumbra. 
This is the character of the shadows cast by 
the earth and moon in space ; for the sun is 
a sphere larger than either the earth or the 
moon. 



AMERICAN HOROLOGICAL JOURNAL. 



137 



To an eye placed in the true conical shadow 
of the moon, the sun is totally eclipsed ; to 
an eye in the penumbra, the sun appears 
horned ; while to an eye placed beyond the 
apex of the conical shadow and within the 
space enclosed by the surface of the cone 
produced, the eclipse is annular. All these 
eclipses are actually seen from time to time 
from the earth's surface. 

The influence of magnitude may be experi- 
mentally illustrated by means of a batswing 
or fishtail flame ; or by a flat oil or paraffine 
flame. Holding an opaque rod between the 
flame and a white screen, the shadow is sharp 
when the edge of the flame is turned towards 
the rod. When the broad surface of the 
flame is pointed to the rod, the real shadow 
is fringed by a penumbra. 

As the distance from the screen increases, 
the penumbra encroaches more and more up- 
on the perfect shadow, and finally obliterates 
it. 

It is the angular magnitude of the sun 
that destroys the sharpness of solar shadows. 
In sunlight, for example, the shadow of a 
hair is sensibly washed away at a few inches 
distance from the surface on which it falls. 
The electric light, on the contrary, emanating 
as it does from small carbon points, casts a 
defined shadow of a hair upon a screen many 
feet distant. 

EXEEEBLEMEXT OF LIGHT BY DISTANCE LAW OF 

INTEL SE SQUARES. 

Light diminishes in intensity as we recede 
from the source of light. If the luminous 
source be a point, the intensity diminishes as 
the square of the distance increases. Calling the 
quantity of light falling upon a given surface 
at the distance of a foot or a yard — 1, the 
quantity falling on it at a distance of 2 feet 
or 2 yards is \, at a distance of 3 feet or 3 
yards it is \, at a distance of 10 feet or 10 
yards it would be -j-i-g-, and so on. This is the 
meaning of the law of inverse squares as ap- 
plied to light. 

Experimental Illustrations. — Place your 
source of light, which may be a candle-flame — 
though the law is in strictness true only for 
points — at a distance say of 9 feet from a white 
screen. Hold a square of pasteboard, or 
some other suitable material, at a distance of 
2 \ feet from the flame, or £th of the distance 



of the screen. The square casts a shadow 
upon the screen. 

Assure yourself that the area of this 
shadow is sixteen times that of the square 
which casts it ; a student of Euclid will see 
in a moment that this must be the case, and 
those who are not geometers can readily satis- 
fy themselves by actual measurement. Divid- 
ing, for example, each side of a sqiiare sheet 
of paper into four equal parts, and folding 
the sheet at the opposite points of division, a 
small square is obtained T Vth of the area of 
the large one. Let this small square, or 
one equal to it, be your shadow- casting 
body. Held at 2 \ feet from the flame, its shad- 
ow upon the screen 9 feet distant will be ex- 
actly covered by the entire sheet of paper. 
When therefore the small square is removed, 
the light that fell upon it is diffused over six- 
teen times the area on the screen ; it is there- 
fose diluted to T Vth of its former intensity. 
That is to say, by augmenting the distance 
four-fold we diminish the light sixteen-fold. 

Make the same experiment by placing a 
square at the distance of 3 feet from the 
source of light and 6 from the screen. The 
shadow now cast by the square will have nine 
times the area of the square itself ; hence the 
light falling on the square is diffused over 
nine times the surface upon the screen. It is 
therefore reduced to \ of its intensity. That 
is to say, by trebling the distance from the 
source of light we diminish the light nine- 
fold. 

Make the same experiment at a distance of 
4| feet from the source. The shadow here 
will be four times the area of the shadow- 
casting square, and the light diffused over the 
greater square will be reduced to |th of its 
former intensity. Thus, by doubling the dis- 
tance from the source of light we reduce the 
intensity of the light four-fold. 

Instead of beginning with the distance of 
2£ feet from the source, we might have begun 
with a distance of 1 foot. The area of the 
shadow in this case would be eighty-one 
times that of the square which casts it ; 
proving that at 9 feet distance the intensity 
of the light is -gf of what it is at 1 foot dis- 
tance. 

Thus when the distances are 

1, 2, 3, 4, 5, 6, 7, 8, 9, etc., 



138 



AMERICAN HOROLOGICAL JOURNAL. 



the relative intensities are 

liii i ii ii p fp 

- 1 ' 4» ¥> T"5"' 3T> '3"S'> 7"5"' "6T> "ST' elo# 

This is the numerical expression of the law of 
inverse squares. 

PHOTOMETRY, OR THE MEASUREMENT OF LIGHT. 

The law just established enables us to com- 
pare one light with another, and to express 
by numbers their relative illuminating pow- 
ers. 

The more intense a light, the darker is the 
shadow which it casts ; in other words, the 
greater is the contrast between the illumi- 
nated and unilluminated surface. 

Place an upright rod in front of a white 
screen and a candle flame at some distance 
behind the rod, the rod casts a shadow upon 
the screen. 

Place a second flame by the side of the 
first, a second shadow is cast, and it is easy 
to arrange matters so that the shadows shall 
be close to each other, thus offering them- 
selves for easy comparison to the eye. If 
when the lights are at the same distance from 
the screen the two shadows are equally dark, 
then the two lights have the same illumina- 
ting power. 

But if one of the shadows be darker than 
the other, it is because its corresjuonding 
light is brighter than the other. Remove 
the brighter light farther from the screen, 
the shadows gradually approximate in depth, 
and at length the eye can perceive no differ- 
ence between them. The shadow correspond- 
ing to each light is now illuminated by the 
other light, and if the shadows are equal it is 
because the quantities of light cast by both 
upon the screen are equal. 

Measure the distances of the two lights 
from the screen, and square these distances. 
The two squares wDl express the relative 
illuminating powers of the two lights. Sup- 
posing one distance to be 3 feet and the 
other 5, the relative illuminating powers are 
as 9 to 25. 

BRIGHTNESS. 

But if light diminishes so rapidly with the 
distance — if, for example, the light of a can- 
dle at the distance of a yard is 100 times 
more intense than at the distance of 10 yards 
— how is it that on looking at lights in 
churches or theatres, or in large rooms, or at 



our street lamps, a light 10 yards off appears 
almost, if not quite, as bright as one close at 
hand ? 

To answer this question I must anticipate 
matters so far as to say that at the back of 
the eye is a screen, woven of nerve filaments, 
named the retina ; and that when we see a 
light distinctly, its image is formed upon this 
screen. This point will be fully developed 
when we come to treat of the eye. Now the 
sense of external brightness depends upon 
the brightness of this internal retinal image, 
and not upon its size. As we retreat from a 
light, its image upon the retina becomes 
smaller, and it is easy to prove that the dimi- 
nution follows the law of inverse squares ; 
that at a double distance the area of the 
retinal image is reduced to one-fourth, at a 
treble distance to one-ninth, and so on. The 
concentration of light accompanying this 
decrease of magnitude exactly atones for the 
diminution due to distance ; hence, if the 
air be clear, the light, within wide variations 
of distance, appears equally bright to the 
observer. 

If an eye could be placed behind the retina, 
the augmentation or diminution of the im- 
age, with the decrease or increase of distance, 
might be actually ob erved. An exceedingly 
simple apparatus enables us to illustrate this 
point. Take a pasteboard or tin tube, three 
or four inches wide and three or four inches 
long, and cover one end of it with a sheet of 
tinfoil, and the other end with tracing paper, 
or ordinary letter paper wetted with oil or 
turpentine. Prick the tinfoil with a needle, 
and turn the aperture towards a candle-flame. 
An inverted image of the flame will be seen 
on the translucent paper screen by the eye 
behind it. As you approach the flame the 
image becomes larger, as you recede from the 
flame the image becomes smaller ; but the 
brightness remains throughout the same. It 
is so with the image upon the retina. 

If a sunbeam be permitted to enter a room 
through a small aperture, the spot of light 
formed on a distant screen will be round, 
whatever be the shape of the aperture ; this 
curious effect is due to the angular mag- 
nitude of the sun. Were the sun a point, the 
light spot w y ould be accurately of the same 
shape as the aperture. Supposing, then., the 



AMERICAN HOROLOGICAL JOURNAL. 



139 



aperture to be square, every point of light 
round the sun's periphery sends a small 
square to the screen. These small squares 
are ranged round a circle corresponding to 
the periphery of the sun ; through their 
blending and overlapping they produce a 
rounded outline. The spots of light which 
fall through the apertures of a tree's foliage 
on the ground are rounded for the same rea- 
son. 

LIGHT REQUIRES TIME TO PASS THROUGH SPACE. 

This was proved in 1675 and 1676 by an 
eminent Dane, named Olaf Roenier, who was 
then engaged with Cassini in Paris in observ- 
ing the eclipses of Jupiter's moons. The 
planet, whose distance from the sun is 475, 
693.000 miles, has lour satellites. We are 
now only concerned with the one nearest to 
the planet. Rcemer watched this moon, saw 
it move round in front of the planet, pass to 
the other side of it, and then plunge into 
Jupiter's shadow, behaving like a lamp sud- 
denly extinguished ; at the other edge of the 
shadow he saw it reappear like a lamp sud- 
denly lighted. The moon thus acted the 
part of a signal light to the astronomer, 
which enabled him to tell exactly its time of 
revolution. The period between two succes- 
sive lightings up of the lunar lamp gave this 
time. It was found to be 42 hours, 28 min- 
utes, and 35 seconds. 

This observation was so accurate, that hav- 
ing determined the moment when the moon 
emerged from the shadow, the moment of its 
hundredth appearance could also be deter- 
mined. In fact it would be 100 times 42 
hours, 28 minutes, 35 seconds, from the first 
observation. 

Roomer's first observation was made when 
the earth was in the part of its orbit nearest 
Jupiter. About six months afterwards, when 
the little moon ought to make its appearance 
for the hundredth time, it was found 
unpunctual, being fully 15 minutes behind its 
calculated t'me. Its appearance, moreover, 
bad been growing gradually later, as the 
e irth retreated towards the part of its orbit 
most distant from Jupiter. 

R j±mer reasoned thus : — " Had I been able 
to remain at the other side of the earth's 
orbit, the moon might have appeared always 
at the proper instant ; an observer placed 



there would probably have seen the moon 15 
minutes ago, the retardation in my case being 
due to the fact that the light requires 15 
minutes to travel from the place where my 
first observation was made to my present 
position." 

This flash of genius was immediately suc- 
ceeded by another. " If the surmise be cor- 
rect," Rcemer reasoned, " then as I approach 
Jupiter along the other side of the earth's 
orbit, the retardation ought to become grad- 
ually less, and when I reach the place of my 
first observation there ought to be no retar- 
dation at all." He found this to be the case, 
and thus proved not only that light required 
time to pass through space, but also deter- 
mined its rate of pi*opagation. 

The velocity of light as determined by 
Roemer is 192,500 miles in a seco.id. 

THE ABERRATION OE LIGHT. 

The astounding velocity assigned to light 
by the observations of Roemer received the 
most striking confirmation from the English 
astronomer Bradley, in the year 1723. In 
Kew Gardens to the present hour there is a 
sundial to mark the spot where Bradley dis- 
covered the aberration of light. 

If we move quickly through a rain-shower 
which falls vertically downwards, the drops 
will no longer seem to fall vertically, but 
will appear to meet us. A similar deflection 
of the stellar rays by the motion of the earth 
in its orbit is called the aberration of light. 

Knowing the speed at which we move 
through a vertical rain-shower, and knowing 
the angle at which the rain-drops appear to 
descend, we can readily calculate the velocity 
of the falling drops of rain. So likewise, 
knowing the velocity of the earth in its orbit, 
and the deflection of the rays of light pro- 
duced by the earth's motion, we can imme- 
diately calculate the velocity of light. 

The velocity of light, as determined by 
Bradley, is 191,515 miles per second — a most 
striking agreement with the result of Roemer. 

This velocity has also been determined by 
experiments over terrestrial distances. M. 
Fizeau found it thus to be 194,677 miles a 
second, while the later experiments of M. 
Foucault made it 185,177 miles a second. 

"A cannon ball," says Sir John Herschel, 
" would require seventeen years to reach the 



140 



AMEKICAN HOKOLOGICAL JOUBNAL. 



sun, yet light travels over the same spr,ce in 
eight minutes. The swiftest bird, at its 
utmost speed, would require nearly three 
weeks to meke the tour of the earth. Light 
performs the same distance in much less time 
than is necessary for a single stroke of its 
wing ; yet its rapidity is but commensurate 
with the distance it has to travel. It is 
demonstrable that light cannot reach our 
system from the nearest of the fixed stars in 
less than five years, and telescopes disclose 
to us objects probably many times more 
remote." 

We shall give from time to time further 
extracts on this and kindred subjects, from 
the same author, as every one dealing in 
optical goods should become familiar with it. 



ANSWERS TO CORRESPONDENTS. 



W. L. M., Mass. — Tradition points to Egypt 
as the birthplace of Alchemy ; and the prob- 
able etymology of the name is that which 
connects it with the most ancient and native 
name of Egypt — Ghemi. It is to the Arabs 
(from whom Europe got the name and the 
art) that we owe the prefix Al. Chemia was 
a generic term, embracing all common ope- 
rations, like the decocting ordinary drugs ; 
but the grand operation of transmuting was 
Al-chemia — the chemistry of chemistries. 

Caligula instituted experiments for produ- 
cing gold out of sulphuret of arsenic. Dio- 
cletian ordered all works on Alchemy to be 
burned ; for multitudes of worthless books 
on this art were appearing, ascribed to fa- 
mous names of antiquity, like Democritus, Py- 
thagoras, and even to Hermes Trismegistus, 
the father of the art. Later the Arabs took 
up the art, and it flourished during the Cali- 
phates of the Abbosides ; and the earliest 
work of this school, written by Gebir — Summa 
Perfectionis (Summit of Perfection) — is the 
oldest known treatise on Chemistry in the 
world. It is a text-book of all then known 
and believed. They had long precipitated, 
sublimed and coagulated chemical substances, 
and worked with gold and mercury, salts and 
acids, and were familiar with a long range of 
what are now called chemicals. Gebir taught 
that there are three elemental chemicals, viz. : 



Mercury, Sulphur and Arsenic ; and these, 
by their potent and penetrating qualities, 
fascinated their minds. They saw mercury 
dissolve gold, the most incorruptible of mat- 
ters, as water dissolves sugar ; and a stick of 
sulphur presented to hot iron penetrated it 
like a spirit, and made it run down in a 
shower of solid drops — a new and remarka- 
ble substance, possessing qualities belonging 
neither to sulphur nor iron. Thus they toiled, 
making many mixtures. Their creed was 
transmutation ; their method blind groping ; 
yet they found many new bodies and invented 
many a useful process. 

Finding its way through Spain into Europe, 
it speedily was entangled with the fantastic 
subtleties of scholastic philosophers. In the 
middle ages it. was the monks who chiefly oc- 
cupied themselves with it, and Pope John 
XXII. delighted in it, though his successor 
forbade it. Eoger Bacon and Albertus Mag- 
nus were the earliest writers on the subject ; 
but the first was the greatest man in the 
school. Strongly condemning magic and ne- 
cromancy, he believed in the convertibility of 
inferior metals into gold ; and he sought even 
more than gold — the Elixir of Life. Like 
Gebir, he believed that gold, dissolved in 
nitro-hydrochloric acid (aqua-regia), was this 
desired Elixir, and urged it on the attention 
of Pope Nicholas IV., and doubtless took 
much of it himself. Magnus was thoroughly 
acquainted with the chemistry of his times; 
he regarded water as nearer the soul of Na- 
ture, the radical source of all things. Thomas 
Aquinas also wrote on the subject, and was 
the first to use the word Amalgam. Kaymond 
Lully, another great name in the annals of 
Alchemy, first introduced the use of symbols 
into Chemistry. Valentine was also celebra- 
ted among the craft, and first introduced An- 
timony into medical use. He inferred the 
Philosopher's stone must be a compound of 
salt, sulphur and mercury, so pure that its 
projection on the baser metals should work 
them into a state of greater purity, till finally 
they should be silver and gold. His practical 
knowledge was so great he was ranked as the 
founder of Analytical Chemistry. But in 
Paracelsus Alchemy culminated. He held, 
with Valentine, that the elements of compound 
bodies were salts, sulphur, and mercury, 



AMERICAN HOROLOGICAL JOURNAL. 



141 



representing respectively earth, air, and water 
— fire being regarded as imponderable. But 
these again were representative; all matter 
was reducible under some one of these typi- 
cal forms; every thing was either cne of these 
forms, or was, like the metals, a compound. 
There was one element common to the four — 
a fifth essence — an unknown and only true 
element, of which the four genuine princi- 
ples were nothing but diminutive forms. In 
short, he believed there was but one elemen- 
tary matter; but what it was no one knew. 
This prime element he considered the univer- 
sal solvent which all sought; to express which 
he introduced the word alcahest. 

After Paracelsus' time the Alchemists were 
divided into two classes. The fi> st was com- 
posed of men of diligence and sense, who 
devoted themselves to the discovery of new 
compounds; practical and observant of facts, 
the legitimate ancestors of the positive chem- 
ists of the era of Lavoiser. The other class 
took up the visionary, fantastical side of older 
Alchemy, carrying it to an extent before un- 
known. Their language is mystical meta- 
phor. The seven metals correspond with the 
seven planets, the seven cosmical angels, and 
the seven openings of the head — the eyes, 
ears, nostrils, and mouth. Silver was Diana; 
Gold, Apollo ; Iron, Mars; Tin, Jupiter; 
Lead, Saturn. They talked of the ascent of 
black eagles, of lily brides; the escape of red 
lions from the embraces of Diana ; their ob- 
ject being merely to disguise a formula for a 
chemical operation. It was long regarded 
as a pure art, vouchsafed to man by the kind- 
ness of Providence, and was the favorite 
study of the clei'gy; hence many mediaeval 
churches contain alchemical symbols. The 
Blue Lion and the Green Lion, the Red Man 
and the "White Woman, the Toad, the Crow, 
the Dragon and the Panther, Crucibles and 
Stars, were blended with the legends of 
Saints and Martyrs. Westminster Abbey, 
many of whose Abbots were notable Alchem- 
ists, is still adorned with many of the em- 
blems of occult science. The magical Pent- 
alpha is still visible in the western windows 
of the southern aisle, and the celestial orbs 
and spheres are figured deep in the pavement 
before the altar. 

It is interesting to observe that the leading 



tenets in the Alchemists' creed, viz., the 
transmutation of other metals into gold and 
silver — a doctrine which once it was thought 
modern chemistry had utterly exploded — re- 
ceives not a little countenance from facts 
every day coming up. The multitude of phe- 
nomena known to chemists under the name 
of Allotropy, are leading prominent chemists 
more and more to the opinion that many 
substances hitherto considered chemically 
distinct, are only the same substance under 
some different condition of its component 
molecules; and that the number of really 
distinct elements may be very few indeed. A 
series of experiments recently performed 
seem to indicate that silver is capable of 
transmutation into another metal, possessing 
some of the properties and characteristics of 
gold. The question of the age then is — as 
of all past ages — what is the interior nature 
of all these elements ? No analytical power 
can move one of these elements from its pro- 
priety. Let synthesis be tried, if analysis 
has failed. It is in the highest degree prob- 
able that all the metals are equidistant from 
simplicity, and all equally compound, if there 
be any truth in the unanimous testimony of 
chemical analogy. Could we but discover 
the secret of one of these tantalizing elements, 
we should know it of all. Boundle s fields 
would then await the explorer. 

F. E. B., Gatlettsburg, Ky. — From India, 
that land of gems, came the first diamond of 
commerce. The most precious among the 
many gems for which that fair tropical land 
is famed. The territory of Nizam — or some- 
times called Golconda, after its most power- 
ful fortress — produced the finest stones. But 
a few centuries exhausted mines in which, for 
untold ages, the pure catbon had been crys- 
tallizing into the limpid jewel. More eagerly 
than the alchemist, bent over his crucible to 
discover the magic stone, and as vainly, have 
scientific men sought to wrest this secret from 
the bosom of the earth. Only in four shapes 
are diamonds cut: the brilliant, the rose, the 
table, and the brilliolette. These last two 
styles are not now used, and are only seen in 
some of the girdle diamonds of " the beauti- 
ful Austrian." The diamonds of the " Queen's 
necklace" were mostly of the rose form, so 
rarely seen in America; i. e., flat on the un- 



142 



AMEBICAN HOEOLOGICAL JOUENAL. 



der surface, and cut into innumerable facets 
on the top. 

The "Koh-i-noor" (Mountain of Light) 
was once part of the aigret of the god Kirs- 
chun; but the poor, powerless god was un- 
able to keep it, for a wild Delhi chieftain took 
it, to grace his tiara of eagle's feathers. 
From chief to chief it passed, till to Aurun- 
zebe it occurred tlat it would be no worse 
for cutting and polishing; but the unskilful 
workman cut it down from 793 to 186 carats. 
Aurunzebe wished to repay him in kind by 
cutting him down also, commencing at his 
head. From this " exceeding great reward " 
he escaped only by instant flight. Soon after, 
Nadir Shah stole it; and from his descend- 
ants it was forced by Achmet, who, in his 
turn, was obliged to resign it to Eunjeet 
Singh; from whom it was taken by the Brit- 
ish troops, and presented to her Most Gra- 
cious Majesty, Victoria, of England. Dissat- 
isfied with its form, which was irregular and 
uncouth, she caused it to be re-cut; thus re- 
ducing it to 106 carats. 

The "Mattan Diamond," three times the 
size of the Koh-i-noor, yet remains with the 
Eajah of Mattan, and caused a bloody civil 
war, of more than twenty years' duration, for 
its possession. It is pear-shaped, and of un- 
speakable brilliancy. Many nations have 
wished to gain it; but, believing the fortunes 
of his race depend on retaining it, he refuses 
all negotiations for it. The " Orloff " is a 
yellow diamond, and is universally conceded 
to be the finest diamond in the civilized 
world. Once the eye of the Indian Poly- 
phemus, it was most zealously guarded by 
the priests of the Temple. To obtain it a 
wily Frenchman became a Pagan; and rising, 
by slow degrees, to the dignity of the priest- 
hood, became, finally, the most devoted wor- 
shipper of the bright-eyed god. Unawed by 
its supposed divinity, he achieved the purpose 
of his life, and stole the stone; and thus, pre- 
eminent among the jewels of the earth, it 
adorned the crown of the Northern Semira- 
inis, where it yet remains. There, too, we 
find the red and the green diamond, of ex- 
quisite lustre and colors. The "Polar Star" 
vies with them in brightness, contrasting its 
limpid purity with their r'eep hues. 

The " Pitt Diamond " (an heir-loom of the 



Orleans branch), is one of the crown jewels 
of France, and was stolen during the Eevolu- 
tion. The thief, not being a crowned head, 
was unable " read his title clear to it," and 
so returned it. The first Napoleon wore it 
on the hilt of his sword. This stone, of 51 
carats, presented to the (late) Empress, by 
her husband, the third Napoleon, is rendered 
even more precious by bearing on its spotless 
surface the name of the most beautiful owner, 
Eugenie. 

The "Sancy Diamond," though only 53| 
carats in weight, ranks high among these 
stones, by reason of its exquisite and unusual 
beauty. Every step of its history is written 
in blood. Though pr< served for centuries in 
the Burgundian family, in some of the fierce 
mediaeval wars it was torn from the body of 
the dying duke, and brought to the King of 
Portugal ; thence the Baron Sancy bought it 
to send, as became so loyal a courtier, to his 
king. The messenger who bore this princely 
treasure was slain by robbers, but not before 
he swallowed the diamond. Eemoved, unin- 
jured, from his dead body, it reached James 
the Second; thence it remained among the 
French crown jewels till the Eevolution. Mis- 
fortune attends it; for Napoleon regained it, 
only to sell it to Prince Demidoff ; from whose 
hands it passed to the Earl of Westmeath, 
and now awaits future transitions among the 
possessions of the late Sir Jametsee Jejeibhoy. 

The " Shah" is among the Eussian crown 
jewels, and is a parallelogram, weighing 86 
carats. It has inscribed on it the name of 
the Persian fire god, in whose temple and to 
whose shrine it was consecrated. 

The "Florentine," like the "Sancy," be- 
longed to the Duke of Burgundy. Taken 
from him by a soldier, after his death on the 
battle field, it reached Pope Julius Second. 
From him the Emperor of Austria obtained 
it, and it is among his crown jewels. Of 139| 
carats, it is not quite flawless, which decreases 
greatly its value. With it is the blue "Hope" 
diamond. Of this rare color there were two; 
but one was stolen from the crown of France, 
and lost. Thus Austria claims the only true 
blue. 

One of the finest diamonds of modern times 
is in the hands of the Castors, of Amsterdam, 
the famous diamond cutters. 



AMEEICAN HOEOLOGICAL JOUENAL. 



143 



"We know of no ring made from a diamond, 
except the one worn by the favorite wife of 
Abdallah, and which was once in the circlet 
of the beautiful Empress Fastrada, beloved 
of Charlemagne, and to which is ascribed 
magic power. 

By referring to No. 7, Vol. I. of the Jour- 
nal, you will obtain the information you de- 
sire, in regard to cutting the diamond. 

In India, the hard rock crystal is called the 
unripe, and the perfect gem the ripe diamond ; 
thus classing it in the vegetable kingdom. In 
the middle ages Europeans thought it an ani- 
mal. Perhaps you have read the story of the 
lady who kept in her casket two rare rose dia- 
monds; and, on taking them from their seclu- 
sion, found, snugly between them, a smaller 
stone; and her delight increased on finding, 
a few months later, another; the loving jew r els 
thus replenishing her treasury as well as the 
earth. This is as well authenticated as other 
medieval legends, and bears equal inherent 
evidence of truth ! 

M. P., Pine Bluff, Ark.— Ho charge the 
needle of a surveyor's compass : Eemove the 
brass centre cap, lay the needle on its side, and 
place over it a strip of soft sheet-iron a little 
longer and wider than the needle. Bringf the 
ends of a horseshoe-magnet in contact with 
the upper surface of the short iron strip, with 
the north end of the magnet towards the 
south end of the needle. Eub the magnet 
back and forth while keeping it upright, at 
the same time firmly holding down the ends 
of the iron strip. The strokes should not be 
much, if any, longer than the needle. End 
th^ rabbing by bringing the magnet to the 
centre, and suddenly remove it by drawing it 
sideways, at right angles to the line of 
the needle and strip. Turn the needle on 
the other side and repeat the operation. 
A dozen strokes of a one or two pound mag- 
net, in good order, will saturate the needle 
with all the magnetism that can be put into 
it by any p ocess. The charging magnet to 
be in good order should be able to sustain 
not less than its own weight It will be 
noticed that in the above operation the mag- 
net does not touch the needle. After the 
needle is charged avoid touching it to any 
iron or steel. Sharpen and finely finish the 
spindle on which the needle turns, and see 



that there is not the least appearance of a pit 
mark where the spindle comes in contact with 
the cap. 

Place the needle on the spindle and allow 
it to settle, noting the exact point to which it 
becomes pointed. Cause it to vibrate, and 
see if it settles again at the same point. 
If not, there is something wrong either in the 
contact [of the spindle and cap, or in the 
magnetism, which must be sought and cor- 
rected. 

For filling engraving, a good quality of 
black sealing wax is best ; if for metal, heat 
hot enough to melt the wax, which rub on 
till entirely filled and covered ; if for wood, 
ivory or pearl, rub it in with a hot iron, 
taking care in either case not to burn the wax. 
Grind off with pumice stone and water as- 
sisted with finely pulverized pumice stone. 

John Seller's gravers are considered as 
good as any. 

L. F., Flemington, N. J. — A pendulum, 
suitable for the clock you mention, like that 
described on page 112, Vol. II., of the Journal, 
would cost you, all complete, about $5. The 
compensation could only be adjusted after 
the pendulum is applied .to the clock, and 
only then by careful experiments. But why 
not make one yourself ? Instead of 43 inches, 
the length of your present pendulum, make 
it 40 inches, which is better, and increase the 
weight of the bob from 25 oz. until the clock 
keeps time. Make your rod round, of soft 
white pine about § inch diameter, and varnish 
with shellac ; fit a ferule on each end to hold 
the spring and screw ; also fit a ferule over 
the rod for the crutch to work on, and alter 
the crutch to the thickness of the rod. For 
the pendulum spring, take a piece of music 
box spring about 1\ inches long, cover the 
ends that are to remain thick with shellac, 
applied with a lamp, and immerse the spring 
in a mixture of about equal parts of nitric 
acid and water for a few minutes, or until the 
part exposed'to the acid is nearly thin enough; 
wash it clean, and grind out all the acid marks 
with an oil-stone slip. Make the compensa- 
tion as described heretofore and you will find 
notrorblein adjusting it. It only requires time 
and patience. If you do not wish to spend 
the time to make it, address B. F. Hope, Sag 
Harbor, N. Y. 



144 



AMERICAN HOROLOG-ICAL JOURNAL. 



You can alter youx breguet spring to make 
the watch go slower if there is any to let out ; 
and of course you can take it up to increase 
the rate ; but if the spring is in good shape it 
should never be disturbed, but bring to time 
by adding to or dimiriisihii g the weight of the 
balance. 

AMERICAN HOROLOGrlCAL JOURNAL, 



PUBLISHED MONTHLY BY 



GI-- 



IB_ MILLER, 

229 Broadivay, N. T., 
At $2.59 per Year, payable in advance. 

A limited number of Advertisements connected 
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received. 

B@°" Mr. J. Herrmann, 21 Northampton 
Square, E. C, London, is our authorized Agent 
for Great Britain. 

All communications should be addressed, 
O. B. MILLER, 
P. 0. Box 6715, New York. 



TO THE WATCH TRADE. 



We are prepared to execute all kinds of difficult 

Watch or Chronometer Repairin 

including replacing any defective parts. 

JOHN BLISS & CO., 

MANUFACTURERS^ CHROMOIETERS, 

60 South Sti eet, N. T. 



J. S. BIRCH'S 

MAGIC WATCH EEY. 

No article introduced to the Trade has given such universal satis- 
faction as Birch's Magic Watch Key. Not only is that the testi- 
mony of all engaged in the wuolesale trade in New York, but the 
luventor is in receipt of tbjusands of letters from practical work- 
men from all pans of the country testifying to the same fact. 

It is with great pleasure that the manufacturer is able to an- 
nounce to the trade that he has completed arrangements by which 
he will in the future be able to supply all orders promptly. He 
would especially invito the attention of watchmakers to the Bench 
Key, which is now brought to a degree of perfection that leaves 
no.hing to be desired. 

The loading features of the Magic Watch Key are, its elf-adjust- 
ing properties — p rfectly fitting itself to any arbor, thereby avoid- 
ing any wear to the corners ; and its simplicity, which renders it 
Impossible to get out of order. 

These keys are well finished, durably made, the squares being of 
the finest tempered steel, ana made perfect square. 

The cut is the exact siz a of the pociet key — the bench key being 
twice the length of the others. 

Price each, 50 cents. Per doz., §4.50. 
Address 

J* $. 81RCH & 00. t 

8 Maiden Lane, JV. Y. 







EQUATION OF TIME TABLE. 




GREENWICH 


MEAN TIME. 




For December, 1870. 








Sidereal 
Time 


Equation 
of 


Equation 
of 




Sidereal 
Time 


fcf 


Day 

of 

Mon. 


of 


Time to be 




Diff. 




a 


the Semi- 


Subtracted 


Added to 


for 


Right 


o 


diameter 
Passing 


from 




Ascension 


Added to 




Hour. 


of 


R 




the 

Meridian. 


Apparent 
Time. 


Mean Time. 




Mean Sun. 






S. 


M. S. 


M. S. 


s. 


H. M. S. 


Th 


1 


70.31 


10 46 18 


10 46.01 ! 0.942 


16 40 33.69 


Fri 


? 


70.39 


10 23 25 


10 23 08 j 0.967 


16 44 30.25 


Sit 


3 


70.47 


9 59 72 


9 59.55 0.991 


16 48 26.81 


Sn 


4 


70 55 


9 35.60 


9 35.44 i 1.015 


16 52 23.36 


TNT 


5 


70.63 


9 10.95 


9 10.79 | 1.038 


16 56 19.92 


Tn 


6 


70.70 


8 45.76 


8 45.60 1.060 


17 16.48 


W. 


7 


70.77 


8 20.03 


8 19.88 i 1.081 


17 4 13.04 


Th. 8 


70 84 


7 53.81 


7 53.67 i 1 101 


17 8 9.59 


Fri 


9 


70.90 


7 27.15 


7 27.01 1.120 


17 12 6.15 


Rat 


10 


70.96 


7 0.05 


6 59.91 1.138 


17 16 2.71 


Sn 


11 


71.01 


6 32.52 


6 32.39 


1.155 


17 19 59.27 


M 


19 


71.06 


6 4.57 


6 4.46 


1.171 


17 23 55.82 


Tn 


13 


71.10 


5 36.28 


5 36 17 


1.186 


17 27 52.38 


W 


14 


71.14 


5 7.64 


5 7.54 


1.199 


17 3148.94 


Th 


15 


71 18 


4 38 70 


4 38.61 ! 1.211 


17 35 45.50 


Fri 


16 


71.21 


4 9.50 


4 9.41 


1.221 


17 39 42.05 


Sat 


17 


71.24 


3 40.07 


3 39 99 


1.230 


17 43 38.61 


Sn 


18 


71 26 


3 10.43 


3 10.36 


1.238 


17 47 35.17 


M 


19 


71.28 


2 40.63 


2 40.57 


1.244 


17 51 31.73 


Tn 


20 


71 29 


2 10 69 


2 10.64 


1.249 


17 55 28.29 


W 


21 


71.30 


1 40.65 


1 40 61 


1.252 


17 59 24.85 


Th 


9,9, 


71.30 


1 10.56 


1 10 53 


1.253 


18 3 21.40 


Fri 


23 


71.30 


40.46 


40 45 


1.252 


18 7 17.96 


Sat 

Sn 


24 
25 


71 29 
71.28 


10.39 


10.40 


1.250 
1.246 


18 11 14.52 


19.61 


19.59 


18 15 11.08 


,r 


26 


71.27 


49.51 


49.49 


1.241 


18 19 7.63 


Tn 


9,7 


71.25 


1 19.27 


1 19.24 


1.235 


18 23 4.19 


w 


28 


71.22 


1 48 85 


1 48 81 


1.227 


18 27 0.7* 


Th 


99 


71 20 


2 18.22 


2 18.17 


1.218 


18 30 57.31 


Fri 


30 


71.17 


2 47.34 


2 47.28 


1.207 


18 34 53.87 


Sat 


31 


71.13 


3 16.19 


3 16.12 


1.195 


18 38 50.42 


Mean time of the Semidiameter passing may be found by sub- 


tracting 0.19 s. from the sidereal 


time. 




The Semidiameter for mean n 


.on may bo assumed the same as 


that for apparent noon. 






PHASES OF 


THE MOON 






r>. 


H. M. 


© Full Moo 
( Last Qua 
@ New Moc 






7 
. 15 


14 39.1 






9 10.9 






22 
.. 29 


18.8 






4 38.1 






D. H. 

5 3.3 






20 15 9 


Latitude of Harvard Observatt 


/ ll 

>ry 42 22 48.1 


H. 


a. s. 


Long. Harvard Observatory . . 


4 44 29.05 


New York City Hall . 


.... 4 5 


3 0.15 




. 5 24 20.572 




5 25 43.20 


Cincinnati Observatorj 


... . 5 37 58.062 


8 


1 42.64 


APPARENT 


APPARENT 


MERII). 


R. ASCENSION. 


DECLINATION. 


PASSAGE- 


D. H. M. S. 


o ' * 


H. M. 


Venus 1 16 22 55.32 


.... 2119 11.1. 


....23 43.7 


Jupiter.... 1 5 29 36.68 


.... + 22 45 6.1. 


....12 46.6 


Satu 


ID. 


.. 1 1 


7 53 12.50 


.... -22 3' 


t 57.6, 


1 12.4 



AMERICAN 





Vol. H. 



NEW YORK, JANUARY, 1871. 



No. 7. 



CONTENTS. 

EsSAT OK THE CONSTRUCTION OF A SlMPLE AND 

Mechanically Perfect Watch— Chap. I. . 145 
Adjustments to Positions, Etc., . *. . . . 152 

Engraving on Jewelry and Plate, 15h 

Metals, 16C 

Travelling Opticians, 163 

Light, ■ ^ . 165 

Answers to Correspondents, 168 

Equation of Tlme Table, 168 

* * * Address all communications for Horological 
Journal to G. B. Miller, P. 0. Box 6715, New York 
City. Publication Office 229 Broaslicay, Boom 19. 



[Entered according to Act of CnngreBS, by G. P. Miller, in the 
oflice of the Librarian of Congress ai Wasnlngtun.J 

E! S S .A. "5T 

ON THE 

CONSTRUCTION OF A SIMPLE AND MECHANI- 
CAL-LI' PERFECT WATCH. 



EY MORRITZ GROSSMANN. 



INTRODUCTION. 

The construction of a good watch is un- 
doubtedly one of the most complicated 
problems in the whole range of practical 
mechanics. The small dimensions not only, 
but also the absolute necessity of confining 
the whole mechanism to a space of a certain 
shape, which must not be transgressed 
nor altered, together with the claims to 
mechanical perfection and exterior elegance, 
are difficulties which may not be encountered 
in the same degree by any other branch of 
engineering. 

The ingenuity and skill of the practical 
horologists have nevertheless contrived many 
different constructions of watch movements, 
and especially in Switzerland, that old centre 
of watch manufacturing, there exists an 
incredible variety of designs, more or less 
happily adapted to their purpose. In review- 
ing so many different expressions of the same 
fundamental idea, the attentive observer will 
not fail to arrive at the conclusion that a 
great part of these different patterns have been 



invented in order to produce something 
novel and original, or to suit some taste or' 
fashion. Some of them, indeed, make ' an 
impression as though a watch were a fancy 
article, and not a scientific instrument. 

This was certainly one of the chief motive3 
which caused the Board of Trade of Geneva 
to open a competition for the study of a sim- 
ple and normal movement. Being impressed 
with the usefulness of a clear treatment of this 
matter, and having become practically 
acquainted with the manufacturing systems 
of Switzerland, England, France, and Ger- 
many, I resolved to enter into this compe- 
tition ; and I had the satisfaction to see that 
my reflections on the subject were favor- 
ably judged and approved by the jurors. 

At the request of the editor of the Ameri- 
can Horological Journal, I have translated 
this Essay, originally written in French, into 
English, at the same time revising and cor- 
recting it carefully, and adding some addi- 
tional remarks especially referring to English 
watches. I am well aware that watch manu- 
facturing in the United States is carried on in 
an altogether different way from what it is any- 
where else. The excessive cost of skilled hand 
labor has led to an extended employment of 
mechanical appliances, and it is really grati- 
fying to learn what amount of skill and saga- 
city has been developed in the construction of 
automatic and self -measuring little machines. 

The system of perfect identity of the parts 
of the movement is certainly very commenda- 
ble, and affords great facilities in manufac- 
turing large quantities. It has already been 
adopted in Paris and Geneva, and the possi- 
bility of maintaining this identity within 
certain limits is no longer doubtful. Still it 
seems to me that this system ought not to be 
extended to the manufacturing of the 
escapement, which, in carefully made watches, 
ought always to be treated as an individual — ■ 
especially the lever escapement. The hori- 



146 



AMERICAN HOROLOGICAL JOURNAL. 



zontal escapement, on the contrary, would 
admit much better an identic treatment. 

Watch manufacturing in Switzerland is 
organized in a very different way from what 
it is in the United States. In Switzerland a 
number of comparatively small establish- 
ments get up the movements — that is, the 
frames, wheels and pinions, barrels and click- 
work. The watch manufacturer orders or 
fcuys them, and gets the casing, motion work, 
escapement and finishing done. The leading 
principles in the construction of the move- 
ments are better not inquired into, as they 
seem to be governed by the taste of the cus- 
tomers rather than by mechanical science. 
This organization gives rise to great irregu- 
larities and inconveniences in manufacturing, 
which has caused several houses of impor- 
tance, especially in Geneva, to create a com- 
plete manufacture of movements for their own 
wants in inclosed localities, much in the same 
way as it is now done in the watch factories 
of the United States. 

The English way of manufacturing presents 
nearly the same general feature, so far as the 
movements are concerned ; but the comple- 
tion of these latter is much more dispersed 
over all the country, and at almost every place 
there are watchmakers who, besides attend- 
ing to their repairing business, do more or less 
in the manufacturing line ; so that compara- 
tively few pure manufacturers, in the Swiss 
style, will be found in that country. This sys- 
tem has the decided advantage of fostering the 
taste for new work, and of affording facilities 
to those desiring to carry out any scheme of 
a new escapement, etc. On the other hand it 
puts the manufacturer of movements rather 
out of the reach of his customers' influence 
and wishes, and this, together with other cir- 
cumstances, must account for many astonish- 
ing imperfections in the getting up of move- 
ments. Many English manufacturers are 
aware of them, but not able to enforce their 
views to the movement makers. In the last 
decade one or two of these latter have begun 
to work on the system of identity, but I have 
not heard anything as to their success. 

The English, Swiss and French manufac- 
turers of movements are exhibiting one com- 
mon inconvenience, viz. : the want of a gene- 
rally acknowledged working standard, and of 



adequate measuring instruments. In France 
and Switzerland the horological population 
hold with uncommon tenacity to the anti- 
quated measuring system based upon the 
"Pied de roi" (the King's foot), though 
neither of these countries has a king. This 
system, in total inharmony with the political 
institutions, with the monetary and measuring 
systems of those countries, and with the 
daily social practice, is entirely impracticable 
for calculation and intercompanson, and not 
very appropriate to the dimensions of watch- 
work, and ought to be abolished and replaced 
by the metric system. If I am correctly 
informed, this latter has been introduced in 
the factories of the Geneva establishments 
above mentioned. 

The English manufacturers are working 
upon the unit of the English inch — still more 
unfit for watch work than the Paris ligne ; 
but the majority of special parts are classified 
by then - makers in arbitrary sizes without any 
reliable standard, and without any guarantee 
that a certain size of one maker is uniform 
with the equally numbered size of another 
maker. The disadvantage of such a state of 
things could not fai] to strike the observation 
of the thinking horologists there; and in fact 
the inconveniences arising from it are ren- 
dered much more perceptible from the fact 
that watch manufacturing is spread all over 
the United Kingdom, while the movements 
and materials are only made in the Lanca- 
shire district. Thus, the London manufac- 
turer has to get his movements — wheels, 
pinions, hands, etc., etc. — from a distance of 
at least one hundred and fifty miles, and it 
is easy to understand that it requires a good 
deal of practice to do this without frequent 
mistakes, owing to the want of a generally 
acknowledged standard of measuring. 

This caused the British Horological Insti- 
tute to issue a circular in 1861, by which 
information was asked about a good and 
practical universal measuring system; and it 
was expressly stated that the suggestions to 
be made should in no way be bound to the ac- 
tual English standard of measuring. I for- 
warded a detailed description of the method 
and instruments in use here in Glashiitte for 
employing the metric system. This was pub- 
lished two years afterwards, and warmly 



AMERICAN HOEOLOGICAL JOURNAL. 



147 



recommended by the special committee ap- 
pointed for the gauge and measuring ques- 
tion. No other communication was pub- 
lished afterwards, except an eccentric gauge, 
which, by its nature, admitted no connection 
with any standard, and so concluded that no 
one had sent another suggestion. Never- 
theless, the opinion of the committee has 
found no followers, and English watch-work 
is, up to the present day, measured by inches 
and their fractions. 

In my Treatise on the Detached Lever 
Escapement,* I expressed my opinions on the 
matter in detail, and tried to prove the per- 
fect applicability of the metric system to 
watch- work, and the calculation of its 
cimensions and proportions. 

It is very much to be regretted that the 
watch factories of the United States had not 
at once introduced the metric measurement, 
which affords so great facilities ; and it 
might have been very easily done, because 
everything had to be created anew, and be- 
cause these factories form, as it were, each a 
world for itself. 

The Swiss watch manufacturers have com- 
plicated their task in a very unnecessary 
way by creating a great variety of sizes of 
movements. Their regular sizes begin at 
10 lignes and go up to 21 lignes, thus giving 
twelve sizes. But a too great readiness to 
meet the most minute exactions of their 
customers, has led them so far as to have 
even sizes by half lignes. The English 
watches have also about seven regular sizes. 
This I think too many, and a gradation by 
1 ligne (about 2.5 mill.) is finer than required 
to meet even the most pronounced taste. If 
five sizes were adopted, differing by 3 mill, 
from each other, the manufacturing would 
be very much simplified. The sizes then 
would be 34, 37, 40, 43 and 46 mill., and 
would embrace the whole range from 15 
to 21 lignes. Watches smaller than 15 lignes, 
or 34 mill., ought not to be made. 

The factories of the United States have 
not made so much concession to the differ- 
ence of taste of the public. So far as I know 
of, they make chiefly two sizes of watches, 
one lor gentlemen and one for ladies. Most 

*T> i/i) bad of Mr. Cbaa. ffm, Schumann, 44 Nassau st.eet, Now 
Yoik. 



likely the equalizing and levelling character 
of the republican institutions of that country 
has assisted them in doing so, and much to 
the advantage and convenience of the trade, 
I am sure. 

To these introductory remarks I will 
merely add that, for establishing the propor- 
tions of the parts of movements, I think it 
the best way to find their relation to the 
diameter of the pillar-plate in as simple frac- 
tions as it can be done. 

According to my opinion, the question : 
What caliper is the best for the cheap produc- 
tion of a simple but mechanically perfect and 
sound watch movement f can best be answered 
by studying the designs already employed, 
as to their relative merits, and by choosing 
the most commendable of them ; or, if the 
actual methods do not seem convenient, by 
creating a new one. 

CHAPTER I. 

THE FBAME. 

1. This part must be the beginning, because 
the way in which it is made influences most 
essentially the physiognomy of the move- 
ment, the arrangement of its organs, and 
even the shape of the case. A watch, as 
well as any other machine constituted mainly 
by rotating parts, requires a frame for sustain- 
ing both ends of each moving axis ; and thia 
frame has to fulfil the same general me- 
chanical requirements as in any other ma- 
chine. 

2. On looking over the frames, as they are 
made in the different manufactories, we may 
distinguish three different modes of construc- 
tion: 

The full plate movement. 

The three-quarter plate movement. 

The movement with cocks — or skeleton move- 
ment. 

AVe will, in the first place, have to compare 
these three systems for the purpose of choos- 
ing the one offering the greatest advantages 
for the fabrication, and the best conditions for 
the solidity and good service of the watch. 

3. The movement with cocks is almost ex- 
clusively adopted in the Swiss manufacturing, 
and it must be acknowledged that it is, more 
than any other one, calculated to exhibit the 
mechanism of the watch favorably to the eye. 



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AMERICAN HOROLOGICAL JOURNAL. 



and give a rich look to the movement. At 
the same time it is of a more complicated 
nature, and it can not be manufactured or 
finished for the same price and in the same 
time of a full or three-quarter plate movement. 
The same observation applies to the taking 
to pieces and putting together ; and it is not 
unlikely that the workmen employed in the 
manufacturing, as well as the repairers, 
would protest against this system if, instead 
of being sanctified by the practice of a rather 
long period, it were to be introduced now. 

4. The frame, with cocks, of a horizontal 
watch requires ten to eleven screws for the 
cocks only, and sixteen steady pins ; the 
frame of a three-quarter plate movement only 
seven screws and six steady pins. Thus, the 

'adjustment of the three pillars balances itself 
by the adjustment of three to four screws and 
nine to ten steady pins; an undeniable advan- 
tage in favor of the three-quarter plate move- 
ment, when cheap and quick manufacturing 
is kept in view. Besides, there are four 
cocks to be made instead of the upper plate, 
and especially the consideration of the shaping 
and finishing of these numerous parts, which 
shows an essential economy in favor of the 
three-quarter plate. 

In repairing, the same inconveniences pre- 
vail; the number of the separate parts is too 
great in the movement with cocks, which 
occasions necessarily a loss of time in the 
operations of taking to pieces and putting 
together. 

5. The stability of the depths, together 
with the vertical position of the pinions, is 
endangered by each bending of a steady pin 
in the frame with cocks. It is for all these 
reasons, that some of the best Swiss manu- 
facturers have dispensed with the cock of 
the third wheel by annexing the hole for 
this wheel to the centre wheel cock, be- 
cause this depth, being the highest above the 
level of the pillar plate, might suffer most 
from the last-mentioned danger. With this 
course of ideas, it is only surprising that the 
same reasons have not at once led to a more 
radical change of system. 

6. It may be asserted as a merit of the 
; movement with cocks, that it affords more 
facility in taking out certain parts ; i. e., the 
barrel, in case of a broken spring, or a piece 



of the click-work, or stop-work in disorder. 
But even this little advantage does no really 
exist, because, for taking out the barrel, if the 
hole in the plate for this latter is not too 
wide, or if the steady pins of the barrel cock 
are rather long, the centre wheel must be 
taken off first, and for doing this ; if the spaces 
are limited, it is often required to lift also the 
cock of the third wheel. Then there are four 
screws to be unscrewed, instead of the three 
of the three-quarter plate. Thus there re- 
mains the more sightly exposition of the 
train as the only advantage of the movement 
with cocks. 

7. The three-quarter plate movement is 
very rarely made in Switzerland ; but so 
much the more in England, where, for about 
twenty years, it has obtained a pronounced 
preference in place of the old full-plate design. 
It secures the relative position and vertical 
standing of the moving axes better than the 
Swiss system, and requires a less number 
of pieces, and less time and trouble in re- 
pairing, still leaving sufficient facility in 
taking out the parts of the escapement. 

8. The arrangement of the train in these 
two kinds of frames is, however, exactly the 
same ; so that any three-quarter plate move- 
ment might be transformed into one with 
cocks by merely taking off the pillars and 
upper plate, and substituting them by cocks 
for each moving axis. 

9. The full-plate movement, on the con- 
trary, admits and even requires a quite dif- 
ferent arrangement of the train. It is the 
most ancient of all frames in watch-work, and 
has been always in great favor in England. 
This kind of frame has also been generally 
adopted by the watch factories of the United 
States. 

10. It affords the possibility of making the 
balance of greater diameter than in any of 
the other frames ; but this is an argument of 
no great importance, because it has long since 
been ascertained that an excessively large bal- 
ance, approaching more to the effect of a fly, 
is not commendable for a good time-keeper. 
Most likely it was the reduction of the size 
of balances which caused the English makers 
to adopt the three-quarter plate movement. 

11. The full-plate frame allows of a much 
easier and more spacious arrangement of the 



AMERICAN HOROLOGICAL JOURNAL. 



149 



train, and especially in fusee movements the 
■wheels and pinions can be made larger than 
in a hree-quarter plate frame, which is cer- 
tainly an advantage. But on the other side, 
for having a main-spring of the same breadth, 
the full-plate movement requires a considera- 
bly greater height of frame and case. This 
•was tolerable at the period when the taste 
required a case with strongly convex backs, 
but the fashion of our days insists upon 
having the backs flat, or nearly so, and this 
caused the necessity of abandoning the full- 
plate system, lest the cases should have too 
disproportionate a height. 

12. The full-plate movement is undeniably 
the most simple ; it can be executed with two 
cocks only (those of the balance), and with 
an economy which no other system affords 
to the same degree. 

13. The taking to pieces and putting to- 
gether of a full-plate watch has inconveni- 
ences which can only be found supportable 
by a long practice with this kind of move- 
ment. The pottance which carries the lower 
balance pivot must necesarily overlap the 
extremity of the fork, or the rim of the es- 
cape wheel in case of a horizontal watch, 
and the workman who takes down the upper 
plate without the necessary precaution, will 
invariably break the lower pivot of the pallet- 
staff, or of the escape pinion in the horizontal 
watch. This happens very often to repair- 
ers who take English watches to pieces with- 
out attentively considering their arrange- 
ment. In fact, to avoid an accident of that 
kind, the movement must be put together 
and taken to pieces on the upper plate, which 
is a very inconvenient method, especially in 
fusee movements, where the tension of the 
main-spring must be adjusted anew after each 
taking down. 

It is true that all these objections might be 
easily eliminated by dispensing with the pot- 
tance, and setting the lower balance hole in 
the pillar plate. But an arrangement of this 
kind wuuld not offer the same certitude of 
position and end shake of the balance staff. 

14 The examining of the escapement, also, 
in a full-plate movement cannot be made 
with the same ease as in a movement other- 
wise arranged. Likewise it is impossible to 
make alterations on the escapement, or to 



j clean it, or give it fresh oil, without taking 
• the whole movement to pieces. 

15. Having thus balanced the merits and 
inconveniences of these three systems of 
movements, it will not be difficult to draw the 
conclusion, that for the watches of our period 
the full-plate movement is not admissible ; and 
that from the two other arrangements remaining, 
the three-quarter movement is preferable for its 
greater solidity and economy in the execution. 

1G. A little saving in the practical execu- 
tion might be attained by omitting the two 
lower bridges. The plate then would only be 
turned out a trifle on the dial side, just to 
make up for any unevenness of the dial. 
The place for the barrel and motion work, 
and even for the lever escapement, can easily 
be provided by circular sinks made on the 
lathe. 

In the same way a little advantage in the 
execution of a three-quarter plate frame w T ould 
result from omitting the pillar, and making 
the upper plate of sufficient thickness to screw 
it directly to the lower plate, securing it in 
position by three good steady pins. For flat 
watches this method is to be recommended, 
as it gives additional solidity. The room for 
the moving parts must be hollowed out on 
the lathe. Watches in thin gold cases, thus 
made with two solid plates, would appear 
more weighty than they would with plates 
of common thickness. The setting of the 
jewels is not so convenient as when it is 
done in the bridges, but with properly ar- 
ranged tools there is no difficulty in setting 
them directly into the plate. 

17. The pillars ought not to be placed close 
to the periphery of the upper plate. On the 
contrary, they will better meet their purpose 
if put a little more inside, because the plates 
cannot be so easily deflected in screwing 
down when the shoulder of the pillar is not 
quite correct and square. The two pillars 
near the barrel ought to be so placed that a 
straight line from the one to the other comes 
as near as possible to the barrel centre. The 
barrel is the reservoir of the moving force, 
and, therefore, the frame must be so arranged 
that it possesses the greatest strength at this 
part. 

18. There is no absolute mechanical neces- 
sity for giving a certain thickness to the plates 



150 



AMEKICAN HOROLOGICAL JOURNAL. 



of the frame, but the pillar plate ought to be 
sufficiently thick to afford a safe hold for good 
strong screws, and to contain the pallet and 
escape wheel so as to be a trifle below the 
surface of the plate. The upper plate ought 
contain the centre wheel in its counter- 
sink flush with the inner surface of the plate; 
and, besides, a solid bearing for the upper 
pivot of the centre pinion should be left. 

According to these necessities, it will be a 
good proportion to make the pillar plate of 
a three-quarter plate or skeleton movement 
0.06 of its diameter. The upper plate ought 
to be about 0.035 of the same diameter. 
These proportions, of course, apply only to 
watches of a mean height (say 0.16, or about 
one-sixth of their diameter); a flat watch, 
having a weaker main-spring, and conse- 
quently less strain on the frame, and less 
pressure on the centre pinion, can bear a 
reduction of these thicknesses. 

19. The material of which the frame is to be 
made is also worthy of consideration. A certain 
degree of elasticity and hardness are required 
for the purpose; besides it ought to offer the 
least frictional resistance to the movement of 
the pivots, and oppose the greatest durability 
to the wear resulting from this motion. 

20. For this last reason steel is out of ques- 
tion here. Besides, it could not possibly be 
protected against rusting, and magnetism 
might endanger the rate of such a watch in a 
most serious way. Still, I will remark here, 
that I had an opportunity of observing for 
many years a good watch, constructed by a 
German maker before jewel holes were at 
convenient reach. He had, for obtaining 
greater durability, screwed steel bushings in- 
to the plates for all the pivots, the escape- 
ment included, and these steel holes, well 
hardened and polished, showed almost no 
wear at all after more than fifty years per- 
formance, and kept the oil remarkably well. 

21. Brass answers fully all the require- 
ments of a good watch frame, if by sufficient 
rolling or hammering it is brought to its 
greatest hardness and density. Hammering 
is preferable to rolling, if possible, because 
this latter process stretches the metal — an 
effect which is not sought for, and which, at 
the same time, does anything but improve 

he quality of the material. Small rollers 



stretch the material more than large ones. 
I have made a rather tedious series of experi- 
ments in order to find out the best way of 
obtaining the greatest possible density of 
brass. For this purpose I constructed a 
small tilt hammer of about 3 lbs. weight, strik- 
ing five to six blows in a second, and adjustable 
to perfect parallelism with its anvil. I found 
that a strip of brass worked with it did not 
show the slightest increase in breadth and 
length — a proof that the considerable amount 
of mechanical work bestowed upon it had 
gone exclusively in the useful direction. By 
comparing I found a strip of 1 millim. thick- 
ness, reduced to 0.9 millim. by this vertical 
hammering, to equal in elasticity a strip of 
3.0 milhm. reduced by rolling to the same 
thickness. This latter was stretched out to 
2| times its former length. 

Thus it is clearly to be seen that the work 
done by the rollers is mostly expended 
in stretching the metal — and that only a 
small fraction of it serves the real purpose. 
This stretching is a source of great injury to 
the solidity of the metal, not only because it 
produces fissures at the edges of the strips, 
but also because it multiplies the size of the 
smallest defects (flaws or holes) in the met il 
to double and triple their size, while vertical 
compression will rather mend them. I could 
not continue my experiments on a larger 
scale, because this little tilt hammer was the 
maximum of what a man can drive with a 
foot-wheel, and I had no machine power at 
my disposal. But the result obtained led 
me to the conclusion that the method general- 
ly used for attaining the necessary density 
and elasticity of brass, is altogether wrong. 
I should prefer to stamp out the rough plates 
and other parts with punch and die from the 
common hard rolled sheet brass to be bought 
in any shop, allowing about 10 per cent, ex- 
tra thickness for the reduction by the vertical 
blow. Then each part ought to be put on a 
flat anvil and submitted to the powerful blow 
of a falling block, adjusted exactly parallel 
to the face of the anvil. Such a method 
would offer another advantage, of making the 
two faces of the blank piece quite smooth and 
level, so that it would not require so much to 
be taken away as when prepared in the usual 
way. 



AMERICAN HOEOLOGICAL JOURNAL. 



151 



22. The plates of English -watches are, as 
a rule, very soft, owing o a bad practice of 
the gilders in exposing them to a high degree 
of heat ; I do not know for what reason, for 
it requires no proof that a very good gilding 
can be effected without heating at all. Their 
upper plates, too, are generally too thin, and 
especially with the screwed jewels, the screw 
heads of which are sunk into the plate ; they 
give very much trouble to the repairer, owing 
to the very small amount of stock left for the 
screw threads in that soft metal. 

23. For some years there has been an in- 
creasing demand for the so-called nickel move- 
meats. These are made of German silver, and 
that incorrect denomination is derived from 
nickel, one of the chief constituents of this 
alloy. There can be no doubt that German 
silver is a first rate material for watch-work, 
from its elasticity and hardness, and I refer 
the reader for farther particulars about this 
matter to the comparative experiments pub- 
lished in my "Essay on the Detached Lever 
Escapement," Chapter XIV. A nicely pol- 
ished and grained German silver movement is 
certainly a handsome looking article, and its 
surface resists remarkably well all atmosphe- 
ric influences, while brass needs to be pro- 
tected by gilding. Still, when touched in a 
careless way with perspiring hands, it gets 
very ugly black stains, and in this particular 
it is inferior to gilt brass. 

In all other points, German silver offers no 
advantage over brass ; and it must be said that 
it is very injurious to the eyes of those who 
have constantly to work at finishing those 
bright polished movements. Brass, at any 
rate, if well prepared, is so nearly equal in 
physical qualities to German silver, that the 
demand for this latter as a material for watch 
movements may be considered a mere matter 
of taste. 

[In wishing our patrons a Happy New Year 
we take pleasure in presenting them with the 
first chapter of Mr. Grossmann's Essay, read 
before the Board of Trade of Geneva, and 
now for the first time published. It is un- 
necessary to say that it will be a work of 
great interest and benefit to the trade, as 
every intelligent horologist is already aware 



that no man now living is considered better 
authority in both practical and scientific 
horology then Mr. Grossmann. It is to be 
presumed that the majority of our readers are 
already familiar with his Treatise on the 
Lever Escapement, but such as are not we 
would advise that they at once procure a 
copy. 

For the benefit of our foreign readers, we 
would state that in the American Watch 
Factories the parts are not interchangeable to 
that degree that might be inferred from Mr. 
Grossmann's remark, but that every escape- 
ment " is treated as an individual," to a cer- 
tain extent, as are also the other parts requir- 
ing a fine adjustment. In the manufacture of 
arms it is possible to have the gauges so per- 
fect that the parts are so nearly perfectly 
identical that a thousand muskets may be 
taken to pieces, and then the parts be taken 
promiscuously and put together again. The 
same results are obtained in the manufacture 
of sewing machines, and many other articles; 
but that will probably never be the case in 
the manufacture of fine watches. 

We are under obligations for very many 
flattering and encouraging letters approving 
our course during the past (which modesty, 
as well as want of space, forbids publishing), 
and shall use our best endeavors to merit the 
good opinion of our friends in the future. In 
a private letter Mr. Grossmann remarks that 
he finds many valuable suggestions in the 
articles from the correspondents of the 
Journal, and we hope to be the recipient 
of still more favors from that source, aa 
there are but few workmen that are not 
capable of giving information on some parti- 
cular point. 

If there are any of our patrons who have 
forgotten to forward their subscriptions for 
the current volume, we would suggest that it 
would be acceptable as soon as the state of 
their finances will admit of it.] 



152 



AMEKICAN HOKOLOGICAL JOUKNAL. 



ADJUSTMENTS TO POSITIONS, ISOCHKONISM 
AND COMPENSATION. 



NUMBER THEEE. 

We will now examine under what circum- 
stances and conditions we can look upon the 

difference as constant for the entire 

p Po 

extent of the hair-spring. 

Suppose, first, that the coils be equal and 
concentric circles, as is the case in the cylin- 
drical hair-spring. Let ABC (Fig. 2) be the 




the law 

P Po 



curve which commences the hair-spring ; A 
being the end fastened, C the point of con- 
junction of the curve and the circle of the 
first coil, meeting it at a tangent. At the 
other extremity the hair-spring terminates 
by an equal and symmetrical curve, the 
end of which, A', corresponds to A, and is 
fastened in the collet of the balance. Now 
the problem is this : see whether we can, for 
all the values, between which the angle a 
varies, deform the hair-spring according to 

£ in such a way that the 

conditions relative to its extremities be 
fulfilled — that is, that the point A and its 
tangent be invariable, and that its opposite 
A' shall always be on the circle of the collet, 
meeting it at a given and constant angle. 
From this moment we may safely conclude that 
whatever may be the form of the terminal 
curves, the condition is very nearly fulfilled — 
since during the general deformation of the 
hair-spring, the point C is very little dis- 
placed, as also the normal C O, on which the 
centre of the first conference is placed; and 
since all the coils assume equal and concen- 
tric circles during the deformation, the point 
C, where the curve C B' A' leaves the coil, 
will be very little off the primitive circum- 
ference of the coils; and the form of C'B' A', 



having itself varied very little during the 
deformation, the extremity A' will meet the 
circumference of the collet at very nearly the 
angle given. We are, then, safe to conclude 
that, in general practice, the pressure, the 
components of which are X and Y, is rela- 
tively very small, and as the coordinates of 
the centre of gravity are also generally infin- 
itely small, the result is, that the quantity 
Yx 1 -Xyj of the equation (3) is negligible in 
the presence of the power G-; that conse- 
quently the isochronism is, if not perfect, at 
least very closely approximated, and that the 
duration of the oscillations of the balance are 
expressed in formula (8). 

Up to this time, we have given pretty much 
a literal translation of the theory of Professor 
Phillips' work, because the preceding embra- 
ces all the fundamental principles upon which 
his subsequent reasoning is based, so that 
the student may be able to verify for himself 
the accuracy of the results; but we shall now 
deviate from this course, and endeavor to give 
the leading features of the work, in plainer 
language, at least where such a proceeding is 
possible. We have said, in the preceding 
article, that the theory of the isochronism is 
here based upon the principle that, during 
arcs of vibrations of the balance, of whatever 
extent, the centre of the coils of the hair- 
spring, as well as the centre of gravity of the 
same, shall always coincide with the centre of 
the axis of the balance. To accomplish this 
result, the hair-spring must be adjusted so 
that during its movements it will be deformed 

according to the law — — — = jj to establish 

which was the leading object of the pre- 
ceding arguments. Now, if the reader has 
attentively followed the reasoning, he will 
understand that this expresses a propor- 
tionality between the angle of motion and 
the length of the hair-spring, which shall 
remain the same though the radii of the 
coils of the hair-spring vary during its 
deformation. The principle of this deforma- 
tion (Fig. 3) will illustrate where the white 
circle represents the coils of the spring in 
their state of equilibrium, and the dotted 
ones the position of the same after the 
deformation has taken place — all concentring 
at the centre 0, which is the centre also. 



AMERICAN HOEOLOGICAL JOURNAL. 



153 



of the axis of the balance, and consequently 
also the centi e of gravity of the spring. By 
a very difiR^'ilt fhain of reasoning, the author 




of the tvoi^ xido uii>co\erea mo j_uo^us of caus- 
ing the hair-spring to vibrate according to 
this law, and these means consist in certain 
fixed terminal curves, according to which the 
ends of the hair-spring must be shaped. We 
will not occupy ourselves with the translation 
of all the mathematical formulas and demon- 
strations evolved, but simply give the re- 
sults of the reasoning, in plain English. As 
before stated, it is the object of the author to 
find the means of keeping the centre of grav- 
ity of the entire hair-spring on the centre of 
the axis of the balance, and that, during all 
angular motions of the balance; to effect this, 
the curves themselves must have their centre 
of gravity on the axis of the balance. The 
conditions of these curves are as follows: 

1st. The ends A A' of the hair-spring (Fig. 
4) must be fastened at half the radius of the 
primitive circles of the coils of the spring, 
and the carves must describe arcs of from 
180° to 270° around the point O. 

2d. The centre of gravity of each of the 
curves must be on the perpendicular D O, let 
fall through the centre to the line C O (Fig. 
5), (which will presently be explained). 

3d. The distance of this centre of gravity 
of the curve to the centre of the coils must be 

equal to -j ; g% being the square of the radius 

of the primitive circle of the coils and I the 
length of the curve; that is, it must be equal 
to a third proportional to the radius of the 
coils and the length of the curve. 

These properties, the author goes on to 
Bay, not only fulfil the conditions of the centre 
of gravity above expressed, but it also hap- 
pens that by reason of these same curves, the 



term neglected in the second member of 
equation (3) becomes, if it may be so. ex- 
pressed, a quantity infinitely small of the 
second order, on the one side because the 
components X and Y are infinitely small, and 
further because the same is true with respect 
to the coordinates of the centre of gravity of 
the hair-spring. 

To show that the centre of gravity of these 
curves coincides with the centre of the coils, 
let ABC (Fief. 4) represpnt one of the curves, 




of which A is the end fastened, and let A'B'C 
represent the other curve, of which the end 
A' is fastened in the collet. The figure sup- 
poses the state of the hair-spring as it is 
before any deformation takes place. Let 
COC'=,3, (3 being any angle whatever. We 
can look upon the hair-spring as forming two 
distinct parts: the first composed of any whole 
number of coils commencing and ending at 
the point C, the centre of gravity of which is 
in O ; the second, comprising the two curves 
and the arc CDC, the centre of gravity of 
which we wish to seek. Now, if G and G ; 
are respectively the centres of gravity of the 
two terminal curves, which are, as we know, 
equal and symetrical, the centre of gravity of 
the two is at the point H, in the middle of 
the line GG'. Moreover, if the angles COG 
and COG' are right angles, the line OH, 
bisecting GOG', prolongated to D, also bisects 
COC, and passes consequently through the 
centre of gravity K, of the arc CDC, from 
which it follows that the angle OGH is equal 
to the angle COK, or to \$. If now, we call 
M the weight of the two terminal curves with 
respect to the point O, and M' that of the 
arc CDC, with respect to the same point we 
have : 



154 



AMERICAN HOROLOGICAL JOURNAL. 



M = 21 X O H = 21 X O G sin \ 

or, M = 2 pg sin I . 

On the other side, by virtue of the law wtich 
gives the centre of gravity of an arc of a 
circle, we have : 

M' = ?l X corde CC 
or, M' = 2?58inJ/?,; 

from which results that 

M = W 
and that consequently the centre of gravity 
of the two terminal curves together, and that 
of the arc C D C, is at the point O, which is 
also the centre of gravity of the entire spring. 
It is to be remarked that this consequence is 
independent of the magnitude of the angle (3, 
or of the interval which separates the points 
and C. 

The author farther proves that this coinci- 
dence of the centres of gravity takes place not 
only in the primitive state of the hair-spring, 
but that it is also a consequence of the 
invariability of the centre of gravity of the 
coils, whatever may be the extent of the angle 
of rotation of the balance. Thus the termi- 
nal curves, indicated by this theory, produce 
the isochronism by satisfying the two condi- 
ditions, to annul all pressure against the axis 
of the balance, and to place the centre of 
gravity of the entire hair-spring on this axis, 
and that, too — which is important to be men- 
tioned — whatever may be the relative posi- 
tions of the two curves, one above the other. 

Moreover, they also possess the properties 
of causing certain perturbations to disappear, 
which are detrimental to the isochronism or 
its preservation; they thus realize the free 
hair-spring, that from which the balance suf- 
fers no pressure, and by which the frictiou 
and its variability, on account of the thick- 
ening of the oil, is reduced to its minimum. 

All the preceding properties of the curves 
subsist, whatever may be the angular space 
which, in the construction of the spring, 
separate its two ends. There is in this angle, 
or what is the same thing, in the total length 
of the hair-spring, an element by means of 
which we may reach the closest possible 
approximation to isochronism, by making it 
longer or shorter. 

In tracing these curves graphically, the 
author proceeds in the following way: he 
supposes that the point A (Fig. 5) at which the 



end of the curve is to be fastened be at half 
the radius of the primitive circle of the coils 
and that the point C, where the curve is to 




leave the coils, be fixed at any angle of be- 
tween 180° to 270° of arc from A around the 
centre O. Draw radius O C, and another 
O D, perpendicular to the first. (The draw- 
ing must be made on an enlarged scale; the 
most convenient may be twenty or thirty 
times the real eize of the hair-spring.) 

Now, a curve is to be found which shall 
have its centre of gravity on this last line 
O D. To this effect we may trace a first 
curve ABC, approximately correct, but 
meeting the coils at C at a tangent; we then 
divide this curve into equal parts, ten or 
twelve, for example, Ca, ab, be, cd, etc., the last 
of which, Aw, shall be the only one generally 
a little smaller than the others. We then 
mark the centre of gravity of each of these 
parts, considering them as small straight 
lines, or, as the case may be, as small arcs of 
a circle; we then measure the distances of 
each of these centres of gravity from the line 
O D, modifying the one relative to An by 
multiplying it by the ratio of An to the com- 
mon length of all the other arcs. With this 
modification, it is to happen that the sum of 
the distances of the centres of gravity which 
are on one side of D shall be equal to the 
sum of the distances of those on the other 
side of O D. If this condition is not fulfilled, 
it will be easy to modify one or the other por- 
tion of the curve in such a manner as to 
arrive at the desired result. This first point 
established, we have yet to satisfy the second 
condition, viz., that the distance G of the 
centre of gravity to the centre of the coils be 

equal to -f> p being the radius of the coils, 



AMERICAN HOROLOGICAL JOURNAL. 



155 



and / the length of the curve ABC. Now 
in order to obtain the distance of the centre 
of gravity of the curve from the centre O, we 
measure the distances of the centres of grav- 
ity of all the little'arcs Ca, ab, be, etc., from the 
line C E, again modifying the one in rela- 
tion to Xn by multiplying it by the ratio of An 
to the lengths of the other little arcs. We 
then take the algebraical sum of all these dis- 
tances, regarding as positive those which are 
on the right of C E, i. e., on the same side as 
H, and as negative those which are on the 
oi;her side; we then multiply this sum by the 
length common to the elements Ca, ab, be, etc., 
and divide the product by the length of the 
curve ABC. The quotient, which will give 
the distance O Gr, shall then be equal to 

-r' Should this equality not take place, it 

will be easy to modify the curve in such a 
manner as to arrive at it, all the while satis- 
fying the first condition. 

In fact, suppose, in order to fix this idea in 
the student's mind, that the distance O G 

thus obtained be greater than — , we can 

take on one side and the other of the point 
B two arcs B M and B N, such that then- 
centre of gravity be on O D, which could be 
easily verified, and substitute for the arc 
M B N an interior one M I N, the centre of 
gravity of which is also on O D, but the sum 
of the distances of which from the line C E 
will be evidently less. It is clear that in this 
way we would very soon arrive at the desired 
results. We can next reduce the curve to its 
real size by a like curve traced around the 
centre of the coils. 

As for the flat hair-spring the preceding 
laws cannot be established except, as we have 
already mentioned, for very small vibra- 
tions of the balance, since it is evident 
that it cannot be constructed so, that 
during angular motions of the balance of 
whatever extent, the centre of gravity of 
the spring shall remain on the centre of the 
axis of the balance. If the laws of the theory 
of Prof. Phillips are true, and they are un- 
questionably proved to be so, any attempt at 
obtaining isochronism in the flat hair-spring 
would seem to be a vain waste of time and 
talents, and indeed most of the theories ad- 



vanced on this subject by workmen are mere 
blind ideas, utterly undemonstrable on the 
ground of any rule or law. 

Different is it with those flat springs the 
outside coil of which is brought back again 
nearer the centre, called Breguet springs. In 
these all the laws applicable to the cylindrical 
ones can be established ; indeed the author 
proves abundantly that it is in no respect in- 
ferior to the cylindrical spring, provided the 
coil brought back again to the centre be 
curved so as to fulfil ^the conditions «;stab- 
lished with respect to the centre of gravity of 
the curve. In addition to this, it is of the 
greatest importance that the flat spring, called 
" Breguet spring," should be as long as pos- 
sible and coiled very closely, for then it will 
deform itself less during the vibrations of the 
balance, open and shut more concentrically 
to the axis, and therefore tend less to press 
the pivots of the balance against the sides 
of the holes ; this is otherwise well known, 
and the necessity of it abundantly proved 
by all writers on the subject. 

Retrospect. — We have seen by equation (4) 
that the power necessary to hold the balance 
in equilibrium against the action of the hair- 
spring is proportionate to the angle which the 
balance has described ; — we shall add to this 
a number of tables of experiments by which 
the author has abundantly proved this rela- 
tion — and we have in this equation the amount 
G expressed in the amount of elasticity of the 
hair-spring, from which it results that the 
angle of motion of the balance is always 
proportionate to the length and elasticity of 
the hair-spring, or vice versa. Directly from 
these principles, and introducing the amount 
of inertia A of the balance, formula (8) has 
been deduced expressing the duration of the 
oscillations of the balance, which is here shown 
to be proportionate to the square root of the 
length of the hair-spring ; — a table of experi- 
ments of the author's will be added, showing 
the manner in which these durations of the 
oscillations vary with the length of the 
springs. In order to make these vibrations 
of the balance isochronal, it has been shown 
necessary that the hair-spring during its 
motions be deformed according to the law 

- — — =j, which law we have illustrated by 



156 



AMERICAN HOROLOGICAL JOURNAL. 



Fig. 3 ; for an illustration of the non-existence 
of this law in the hair-spring and its conse- 
quences, we add Fig. 6, where the white 
circle again indicates the coils of the spring 
in their n**i™i+-'ve position, but where the 




radii of tne ciroiou oi tne cous vtny unequally 
according to the angle of motion, and with 
respect to the centre of the axis of the balance, 
as represented by the dotted circles. The 
means of establishing this law in the spring 
the author has discovered in certain terminal 
curves, the conditions and finding of which 
are shown and illustrated by Figs. 4 and 5. 

It would be impossible to prove to the un- 
initiated all the reasons, the whys and the 
wherefores of these results, so that they 
should be able to grasp it ; to do this it would 
be necessary to teach them all the branches of 
mathematical science, the highest not except- 
ed ; but it is to be hoped that those at least who 
are desirous of learning to work correctly 
and according to sound principles will be 
benefited, inasmuch as it will stimulate 
them to research. "We may mention that a 
complete translation of the entire work of 
Prof. Phillips on the hair-spring, combined 
with explanations and references, is proposed 
by the writer of this, should it be found likely 
to recompense him for the cost and labor. 
Those who would think it of sufficient interest 
to possess such a work may indicate it to the 
editor of the Journal. 

The following tables contain experiments 
made with a view to test the influence of the- 
oretical curves as to the isochronism of the 
vibrations. In these experiments an elastic 
balance has been used weighing nearly one 
milligramme, by means of which the force 
necessary to maintain the balance at certain 
angles from its primitive position of equilib- 



rium, has been measured, and the law of the 
proportionality between force and the angle 
of motion tested and proved. The tables 
will explain themselves. 

First Experiment. — Hair-spring with theo- 
retically curved extremes, but having only 1\ 
coils. 



Angles- 


Force in 
Grammes- 


Loss of Angle 
by permanent 
Deformation. 


Force reduced 

to 22£° by the 

proportion of 

the angles. 


Decrees- 


Grammes. 


Decrees. 


Grammes. 


22J 


1 542 


0. 


1.542 


45 


3.084 


0. 


1.542 


67^ 


4.620 


1 


1.5423 


90 


6 150 


0.166 


1.5404 


135 


9.222 


0.2 


1.5393 


180 


12.305 


0.26 


1.5404 


225 


15.360 


0.35 


1.5384 


270 


18.440 


0.6 


1.5401 



It may be seen by the fourth column that 
the proportionality is as nearly perfect as pos- 
sible, and yet it must be remembered that 
the spring had but 1\ coils, and that there 
was some slight friction. 

The second experiment has been made with 
a spring a little longer but having extreme 
curves made far from combining any theoret- 
ical conditions. 

Second Experiment. — Spring with 8 coils, 
curves not theoretical. 





Force in 
Grammes. 


Loss of Angle 


Force reduced 


Angles. 


by permanent 


to the Propor- 




deformation. 


tion of 22i°. 


Degrees. 


Grammes. 


Deerreess. 


Gramma. 


22* 


1 500 


0. 


1.500 


45 


2.983 


0. 


1.4915 


67* 


4 461 


0. 


1.4870 


90 


5.930 


0.5 


1.4833 


135 


8 875 


0.15 


1.4808 


180 


11.815 


0.20 


1.4823 


225 


14.807 


0.27 


1.4825 


270 


17.820 


0.50 


1.4878 



It will suffice to compare the 4th column 
of this table with the preceding experiment 
to see at once that the law of the proportion- 
ality is much less perfect in this. 

The next two experiments were made with 
hair-springs of but 4 coils, made of steel 
which was not very homogeneous. The ter- 
minal curves of one were made theoretically, 
those of the other not. 

Third Experiment.— Saving with 4 coils — 



AMERICAN HOROLOGICAL JOURNAL. 



157 



steel not very homogeneous — with theoretical- 
ly made curves. 





Force in 
Grammes. 


Loss of Ancle 


Force reduced 


Angles. 


bv permanent 


to the Propor- 




Deformation. 


tion of 22£°. 


Decree?. 


Grammes. 


Decrees. 


Grammes. 


22$ 


1.542 


0.3 


1.5628 


45 


3.092 


0.4 


1.5600 


90 


6.215 


0.5 


1 5624 


180 


12.472 


0.6 


1 5642 


270 


18.581 


2.2 


1.5611 



We see that the proportionality is yet very 
nearly perfect. 

Fourth Experiment. — Spring with 4 coils — 
6teel not very homogeneous — with terminal 
curves not made theoretically. 



Angles. 



Force in 
Grammes. 



Loss of Angle 
by permanent 
Deformation. 



Decrees. 

22$ 

45 

90 
180 
270 



grammes. 

1.569 

3.150 

6 271 

12 475 

18.780 



Decrees. 
0.1 
0.2 
0.4 
0.6 
0.9 



Force reduced 
to the Propor- 
tion of 22i°. 



Grammes. 
1.5760 
1 5820 
1 5747 
1.5646 
1.5703 



We see that notwithstanding the bad qual- 
ity of steel, and the small number of coils, 
the preceding spring gives very nearly the 
proportionality, while the last one is very far 
from doing so. 

The foil owing four experiments were made 
with the hair-springs of the first and the sec- 
ond experiments ; but they are interesting in 
as much as, the friction having been dimin- 
ished, the spring with theoretical curves still 
showed great advantage over the other. 

Fifth Experiment. — Spring of the first ex- 
periment with theoretical curves, with the 
.•iction of the balance diminished. 



Angles. 


Force in 


Loss of Angle 
by permanent 
Deformation. 


Force reduced 
to the propor- 






tion of 22±°. 


Degrees. 


Grammes. 


Degrees. 


Grammes. 


22$ 


1.538 





1.5380 


45 


3.076 





5380 


67$ 


4.611 


0.05 


1 5381 


90 


6.132 


0.25 


1.5375 


135 


9 219 


0.17 


1.5384 


180 


12 286 


40 


1 5390 


225 


15.366 


0.37 


1.5390 


270 


18.470 


0.45 


1.5387 



We see that the proportionality is very 
close. 

Sixth Experiment. — Spring of the second 
experiment — curves not theoretical— but with 
the balance of the fifth experiment. 





Force in 
Grammes. 


Loss of Angle 


Force reduced 


Angles. 


bv Permanent 
Deformation. 


to the propor- 
tion of 22$°. 


Degrees. 


Grammes. 


Degrees. 


Grammes. 


22$ 


1 500 


0. 


1 . 5000 


45 


3 002 


05 


1 5027 


67± 


4.489 


0. 


1.4963 


90 


5.967 


0.05 


1.4926 


135 


8 938 


05 


1 4902 


180 


11.906 


0.125 


1.4893 


225 


14 866 


23 


1 4881 


270 


17.872 


0.25 


1.4907 



We see the proportionality is much less ap- 
proximated here, than in the preceding exper- 
iment. 

Seventh Experiment. — Spring of the first 
experiment — theoretical curves— but with a 
smaller balance, and the friction very much 
reduced. 





Force in 
Grammes. 


Loss of Angle 


Force reduced 


Angles. 


by permanent 


to the propor- 




Deformation. 


tion of 22$* 


Degrees. 


Grammes. 


Degrees. 


Grammes. 


22$ 


1 565 





1.5650 


45 


3 130 





1.5650 


67$ 


4.692 


0.05 


1.5651 


90 


6.261 





1 5652 


135 


9.381 


0.143 


1.5652 


180 


12 500 


0.333 


1.5654 


225 


15 640 


0.10 


1.5647 


270 


18.757 


0.20 


1 5643 



Eighth Experiment. — Spring of the second 
experiment — curves not theoretical — but with 
the balance of the seventh experiment. 







Loss of Angle 


Force reduced 


Angles. 


Force. 


by permanent 


to the propor- 






Deformation. 


tion of 22$°. 


Degrees. 


Grammes. 


Degrees. 


Grammes. 


22$ 


1 507 


05 


1.5103 


45 ^ 


3.024 


0.10 


1.5153 


67$ 


4 538 


0.10 


1.5149 


90 


6.055 


0.143 


1.5161 


135 


9 . 073 


25 


1.5150 


180 


12.106 


. 333 


1.5160 


225 


15.146 


5 


1.5180 


270 


18.198 


0.5 


1.5193 



We see that the spring of the seventh 
experiment has still considerable advantage 
over that of the eighth. 



158 



AMEBICAN HOKOLOGICAL JOUKNAL. 



It has been shown that the duration of the 
oscillations of the balance is proportionate to 
the square root of the length of the hair- 
spring. The following table will permit us to 
Bee at once the manner in which the duration 
varies with the length of the hair-spring. 

Table showing the proportion of the number of vibrations 
of the balance in a given time, to the different lengths of a 
hair-spring. 





Proportion of the 




Proportion of 


Proportion of 


lumber of vi- 


Proportion of; 


.he number of 


the lengths of 


)rations of the 


thelengthsof 


vibrations of 


a hair-spring. 


lalance in a 


a hair-spring. 


he balance in a 




given time. 




given time. 


0.99 


1.0050 


0.59 


1.3019 


0.98 


1.0101 


0.58 


1.3133 


0.97 


1.0153 


0.57 


1.3245 


0.96 


1.0206 


0.56 


1.3363 


0.95 


1.0260 


55 


1 . 3484 


0.94 


1.0314 


0.54 


1.3608 


0.93 


1.0370 


0.53 


1.3736 


0.92 


1.0426 


0.52 


1.3867 


0.91 


1.0483 


0.51 


1 . 4003 


0.90 


1.0541 


0.50 


1.4142 


0.89 


1.0600 


0.49 


1.4286 


0.88 


1.0660 


0.48 


1.4434 


87 


1.0721 


0.47 


1.4587 


0.86 


1.0783 


0.46 


1 4744 


0.85 


1 0846 


45 


1.4907 


0.84 


1.0911 


0.44 


1 5076 


0.83 


1 0977 


0.43 


1.5250 


0.82 


1.1043 


0.42 


1.5430 


0.81 


1.1111 


41 


1.5618 


0.80 


1.1180 


0.40 


1.5811 


0.T9 


1 1251 


0.39 


1.6013 


0.78 


1.1323 


0.38 


1.6222 


0.77 


1.1396 


0.37 


1.6440 


0.7(5 


1.1471 


0.36 


1.6667 


0.75 


1.1547 


0.35 


1 . 6903 


0.74 


1.1625 


34 


1 7150 


0.73 


1.1704 


0.33 


1 7408 


0.72 


1.1785 


0.32 


1.7677 


0.71 


1 1868 


0.31 


1.7960 


0.70 


1.1952 


0.30 


1 8257 


0.09 


1.2038 


0.29 


1 8570 


(58 


1.2127 


0.28 


1.8898 


0.67 


1 2217 


0.27 


1 9245 


0.GG 


1.2309 


0.26 


1.9612 


0.65 


1.2403 


0.25 


2.0000 


64 


1.2500 


0.24 


2.0412 


0.63 


1.2599 


23 


2 0851 


62 


1.2700 


22 


2. 1320 


0.61 


1.2803 


0.21 


2.1822 


0.60 


1.2910 


0.20 


2.2361 


HoROLOGIST. 


RNGfij 


LYING ON JEWELRY AND 


PLATE. 



For lettering upon jewelry and plate it is 
necessary to have thirty or forty gravers — 
several being required similar in shape to 
those used by engravers on wood or steel. 
These tools are straight on the bottom, the 
width making the different degrees of fine- 
ness ; but for gold or silver ware that is hol- 
lowed the straight tool cannot be used; it is 



necessary that the points of the gravers turn 
upwards. In several tools the points may be 
turned up sufficiently by grinding the 
tool on an oil-stone, but in others the tool is 
bent upwards, as much as required, 
before it is hardened — the face being made 
as in other gravers. By " face," we mean the 
end of the tool that is ground on the oil-stone 
to sharpen it. An oil-stone for sharpening 
tools is, of course, essential, and must be 
of fine quality, and sweet oil is the best for 
using on it. 

A stand, with an arm to hold a magnifying 
glass, is required; the arm having a joint in it, 
with a screw, which permits the glass to be 
placed on any required plane. Pads or cush- 
ions of several sizes are required — some 
being little more than two inches across — 
and are used singly or together, one on top 
of another. They are also stuffed to different 
degrees of hardness; some being so soft that 
the article to be engraved may be indented 
into it. 

To hold the various articles in place, sev- 
eral small adjuncts are necessary. For 
holding knives, spoons, etc., small clamps are 
required ; these are made of wood, and are 
about four inches high, and at the top about 
two inches in diameter — one diameter, how- 
ever, being greater than the other — the shape 
of the top being a flattened circle. This clamp 
is divided in halves, slightly hollowed inside, 
and joined together by a hinge at the bottom. 
At the opening on the top the wood is grooved 
to make a rest for the fork, spoon, or other 
article to which it may be applied. The top, 
with its groove, is capped with brass, and 
narrow slips of leather or metal are laid into 
the groove, according to the thickness of the 
plate placed in it — it being essential that the 
surface to be engraved shall be level with the 
top of the clamp. 

Half way from the bottom 4 to the top a 
screw permits the top to be opened to the 
proper width for the article to be placed in 
the rest, and holding it firmly while being 
engraved. When rings are engraved on the 
outside, they are slipped on smooth sticks, 
which are tapered to fit different sizes of rings, 
To engrave inside, the engra'v ex holds the ring 
in his fingers, resting it on the cushion. 
Napkin rings, pencils, heads of canes, card* 



AMERICAN HOROLOGICAL JOURNAL. 



19 



cases, etc., are also held by the fingers. To 
hold a thin plate of metal in place blocks of 
wood are used, small tacks at the edges of 
the plate keeping it in place. A steel bur- 
nisher is required by the silver engraver, also 
a set of mathematical drawing tools, and 
hones, covered with buff leather, to remove 
the finger marks from the surface of the 
metal. 

To prepare an article for engraving, the en- 
graver dims the surface with candle grease, 
which he applies with his fingers, a very 
slight quantity being sufficient. 

To rule straight lines on a flat surface, a 
small, thin steel rule is used. This is reo- 
tangTilar in shape, with a rectangular opening, 
leaving on one side and the ends a third of 
an inch of metal ; on the other side two-thirds 
of an inch is left. To rule lines on a circular 
surface, as for instance a cup, or round nap- 
kin ring, a pencil-holder is fastened at right 
angles to a short rod of steel, which the en- 
graver holds between his fingers at the edge 
of the article, and turning it carefully makes 
his lines parallel with the top. We have 
seen a rod which was adjusted with a flex- 
ible joint and screw, which enabled the en- 
graver to set his pencil at whatever angle he 
might require for the article on which he was 
at work. This is especially serviceable for the 
inside of silver ware, such as a cake basket. 
The "pencil" used is made of boxwood, 
pointed, and although its point will trace lines 
on the dimmed surface, it will not scratch the 
metal. Formerly steel points were used, and 
where the lines traced were guide lines, it 
was necessary, after the lettering was done, 
to remove them with the burnisher. The 
boxwood point, it may be seen, is a great 
improvement. 

The engraver also uses these boxwood pen- 
cils to sketch out the letters he desires to 
engrave; then, according to the shape of the 
article, he selects a suitable graver for the 
lettering. When requisite that a set of spoons, 
knives, etc., shall be marked alike, one article 
is engraved with the letters selected; after 
which the surface is spread with a coat of 
candle grease, which is carefully filled into 
the lettering, and the superfluous grease is 
removed from the face of the article, leaving 
the letters filled. A piece of dampened woven 



letter paper is then laid over the lettering, 
and, with a burnisher, an impression of 
the edge of the article is rubbed on the 
paper, which serves for a guide to place 
the paper on every article in the same posi- 
tion. A second piece of paper is laid on, and 
the burnisher is rubbed over the lettering till an 
impression in grease is printed on the paper. 
This impression is now ready to trace upon 
the gold or silver as many copies as are 
required. At first a slight pressure with the 
fingers is sufficient to make a trace upon the 
surface of the metal; afterwards the burnisher 
is required. One of these impressions will 
usually trace two dozen articles. The proper 
gravers are selected, and the letters cut in 
this tracing— the hair lines and the broad 
lines being cut at different degrees of depth. 
It is usual to prepare in the copy from which 
the tracing is made only the body of the let- 
ter; the ornamental dots and points being 
added to each duplicate by the engraver — 
eye-practice giving him precision in this 
respect. After the article is engraved it is 
wiped clean with chamois skin, no trace of 
the grease remaining. 

Shades and screens for the protecting of 
the eyes are adjusted according to the exigen- 
cies of the place in which the engraver is 
obliged to work; it being generally conceded 
that a north exposure gives a clearer, steadier 
light than any other, but shades may be 
adjusted so that any exposure may be used. 
The rule should be, to have sufficient light on 
the work to see well, but a glare should be 
avoided. It is important that the light fall 
on the work and the eyes be shaded. Atten- 
tion in this respect will enable the engraver 
to see better, and not wear out his eyes. 

In ornamental engraving many of the tools 
used are similar to those used by letter 
engravers on steel, or flat silver surfaces; 
technically, by the ornamental engraver, they 
are called " line gravers." But to perform 
most of the ornamental engraving tools are 
required with fine lines cut into the bottom 
of the tool, and when held steadily on 
the plate a series of fine lines are cut, 
known as shading. Some of these tools make 
only two lines, and others make three, four, 
five, or six; they are generally straight on 
the bottom, and, in engraving, the hand is 



160 



AMERICAN HOROLOGICAL JOURNAL. 



held high, so that the point of the tool 
touches the plate, the left hand moving it as 
the design requires. At present the orna- 
mentation in vogue is called "bright work," 
and is produced by holding the tool as afore- 
said, and wriggling it in short, rapid turns, 
the left hand turning the article. When this 
wriggling is done rapidly the wave effect pro- 
duced on the lines cut is almost impercepti- 
ble to the naked eye. The lines made by 
this method are so delicate that the light falls 
on them in such a manner that it makes the 
design look white on the tinted back-ground 
of gold or silver, and a large variety of orna- 
mental leaves, scrolls, etc., may be executed 
with these tools. 

For figures, animals, scrolls in outline, etc., 
the line gravers are best adapted. Many 
designs employ the several kinds of tools, 
which are sharpened on an oil-stone, the 
same as other gravers, but for " bright work '' 
it is necessary that they be polished upon a 
block of wood covered with rouge and oil, 
which imparts a polish to the tool that en- 
ables the engraver to cut his work with great 
brilliancy and beauty of effect. The orna- 
mental engraver preserves proofs of his works 
on paper, the same as steel-plate engravers, 
which are used to trace the design again 
when required. 

An original design is drawn on paper, which 
is then perforated with a fine needle and laid 
upon the article to be engraved ; pumice 
powder is then beat upon the paper, the de- 
sign being traced on the plate in fine dots. 
To preserve a facsimile of the engraving 
on a flat surface, printers' ink is rubbed into 
the lines, the surface being wiped clean in the 
same manner that a steel plate is prepared 
for printing ; but a silver salver or cake 
basket cannot be made to pass through a 
printing press ; so, to get an impression from 
them, some plaster of Paris is wet with water 
to the consistency of batter and poured over 
the whole article. It is allowed to become 
set and dry, and being then removed from 
the silver ware, a perfect representation, in 
black, of the design is printed on a white 
surface. 

This department of ornamental engraving 
sometimes is classed under the head of en- 
chasing, but is properly called engraving, 



because the tools and manipulation are those 
of the engraver, rather than of the enchaser. 



METALS. 

It may be somewhat of interest to part of 
our readers, and possibly of advantage to 
others, to know something of the various 
metals in existence. A volume would not 
suffice to give the history, properties, mod> 
fications, and known relations of them all, 
and we can give space to. no more than a 
meagre outline. 

Of all the elementary substances — that is, 
substances whose constituent parts (if they 
are not simples) have not yet been resolved — • 
the metals form far the most numerous class, 
and their importance in the useful arts is 
equal to their extent. They are diffused uni- 
versally and very equally through the earth's 
crust ; some are rare, others are extremely 
abundant; some of the most importance in 
the metallic state, others in combination with 
oxygen, sulphur, phosphorus, or whatever 
else. Their properties are so numerous that 
we must refer to a few of them only, under 
their respective heads. There are certain 
properties in which all metals agree ; they 
all have metallic lustre ; they are all good 
conductors of heat and electricity, and are 
electro-positive; that is, when a metallic com- 
pound is decomposed by the electric current, 
the metal is given off at the cathode or nega- 
tive pole. 

The most striking property of the metals 
is then- lustre, which serves to distinguish 
them from the non-metallic elements. This 
lustre is evident, whether the metals be in 
masses or in fragments ; even when in fine 
dust it can be made evident by means of an 
agate burnisher. The lustre seems to depend 
on the opacity of the metals, and on the 
facility with which they take a polish, more 
or less perfect ; hence they are adapted emi- 
nently to reflect light, since their opacity 
prevents the transmission, and their polish 
the absorption of luminous rays. There are, 
however, a few exceptions to the perfect 
opacity of metals, for gold leaf transmits 
green rays, and leaf of the alloy of gold and 
silver transmits blue rays. 



AMERICAN HOROLOGICAL JOURNAL. 



1G1 



The colors of the metals are various. Cop- 
per and titanium are red, bismuth is pinkish, 
gold is yellow, and all the others possess a cer- 
tain degree of uniformity, ranging from the 
pure white of silver to the bluish-grey tint of 
lead. The metals differ so much in their 
densities that while potassium is lighter than 
water, platinum is twenty-one times heavier 
than that fluid. 

The following table gives the specific grav- 
ities of the more common and well known 
metals : 





20.98 

19.26 
17.60 

13.57 

11.30+ 

11.35 

10 47 

... . 9.82 

9.00 




... 7.79 


Gold 

Mercury 

Lead 


Tin: 


7.40 
7.29 
6.86 + 
6 85 
... 6.70 


Silver 




... 6 11 






. .. 5.88 






... 5 30 




8.89 
8 . 60 




... 2.00 




... 1.70 


Cobalt 


8.54 
.... 8.28 


0.972 
... 0.865 



All these metals differ in hardness as much 
as they differ in density; for while some are 
very hard, others can be scratched by the 
thumb-nail, or even moulded, like wax, be- 
tween the fingers. The following table shows 
the relative degrees of hardness of some of 
them : 

Titanium, Manganese — harder than steel. 

Platinum, Palladium, Copper, Gold, Silver, 
Tellurium, Bismuth, Cadmium, Tin — scratch- 
ed by Calc. spar. 

Chromium, Rhodium — scratch glass. 

Nickel, Cobalt, Iron, Antimony, Zinc — 
scratched by glass. 

Lead — scratched by the nail. 

Potassium, Sodium — soft as wax. 

Mercury — licpxid at ordinary temperature. 

All the metals are supposed to have the 
property of assuming the crystalline form; 
but it is not always easy to place them under 
conditions favorable to their doing so. Many 
of them occur in nature, in what is called the 
native state, in a crystalline form, particularly 
gold, silver, copper, and bismuth ; some 
crystallize when reduced to a fluid state and 
allowed to cool slowly. When a solid crust 
has formed on the surface, if the fluid metal 
be poured out from within, the interior of the 
crust will be found lined with crystals. 
Crystals of antimony, lead, and tin, may be 
obtained in this way, but not so easily as with 



bismuth — larger masses of metal and slower 
cooling being required. In iron foundries 
crystals of that metal have been found in the 
midst of large masses, which have been allow- 
ed to cool slowly. 

Some metals are precipitated in a crystal- 
line form from a solution of their salts by 
another metal; a strip of zinc, in a solution 
of acetate of lead, precipitates the lead in 
feathery crystals; silver is thus deposited by 
mercury, and gold from an ethereal solution 
by a stick of phosphorus. Electric currents 
of feeble intensity produce crystals from 
metallic solutions, and it may be owing to 
this action within the earth's crust, that many 
of the metals are found in a native crystalline 
form. 

Metals are more or less valuable in the 
arts in proportion to their ductility and mal- 
leability, which permits them to be drawn 
into wire, and beaten or pressed into thin 
leaves. The following list is arranged in the 
order of malleability: 

Gold, Zinc, 

Silver, Iron, 

Copper, Nickel, 

i n, Palladium, 

Cadmium, Potassium, 

Platinum, Sodium. 
Lead, 

The ductility of the metals does not follow 
the order of their malleability, as the follow- 
ing table will show : 

Gold, Zinc, 

Silver, Tin, 

Platinum, Lead, 

Iron, Palladium, 

Nickel, Cadmium. 
Copper, 

The ductility of metals depends upon their 
tenacity, or power of resisting the tension 
necessary to apply to them in forcing them 
through the holes of the draw plate, which is 
simply applying sufficient force to cause the 
particles of metal to flow in front of the plate, 
as has been shown clearly in one of the earlier 
numbers of the Journal. 

Silver can be drawU into wire -g^ of an 
inch in diameter, and by enveloping an ingot 
of gold with silver previous to driwing, a 
single grain of gold may be drawn into a 
wire 550 feet long; this wire is covered with 
silver, which may be removed by dilute 



162 



AMEKICAN HOKOLOGICAL JOUKNAL. 



nitriG acid, leaving the enclosed gold wire only 
the 6 O x j of an inch in diameter. Platinum 
has been drawn in this manner to the ginnnj- 
of an inch in diameter. 

The tenacity of metals is the power which 
they possess of resisting tension without 
breaking. It varies with the different metals, 
and the following table will show their relative 
tenacity as compared among themselves. 
The following weights are sustained by wires 
0.787 of a line in diameter. 

Iron 249.250 lbs. I Gold 150.753 lbs. 

Copper ...302.278 " | Zinc 109.510 " 

Platinum 274.320 " Tin 34.630 " 

Silver 187.237 " | Lead 27.621 " 

The tenacity varies greatly in the same 
metal, with its purity and its method of prep- 
aration, it being much diminished bv anneal- 
ing. A soft iron wire which sustained a 
weight of 26 lbs., after annealing broke with 
a weight of only 12 lbs., and one of copper 
which sustained 22 lbs. before annealing, was 
broken by 9 lbs. after being annealed. The 
process of annealing seems to have removed 
the particles to a greater distance from each 
other, thus diminishing the cohesive attrac- 
tion between the particles by just so much 
as the annealing has separated them. 

The conducting powers of the metals are 
as various as their other qualities, and their 
examination property comes in the series of 
articles on heat which we are now publish- 
ing, as does also their fusibility. Some of the 
metals, if slightly elevated in temperature, par- 
ticularly by friction, evolve an odor which is 
quite perceptible to sensitive organs of smell. 
We have known persons who could detect a 
plated article by the frictional odor of the 
enclosed base metal. 

Copper, iron, and tin are especially notice- 
able for this quality of odor, and also for 
their metallic taste. 

The harder metals are also elastic, and 
consequently more or less sonorous, but these 
qualities are more conspicuous in alloys 
which are formed by certain combinations of 
metals with each other. This subject of the 
alloy of metals is one of the most important 
of their properties, and in its ramifications 
and uses embraces every department of art; 
and is, in fact, as fascinating to some minds 
as the subject of perpetual motion to others. 



We do think, and must say, that it is one of 
the branches of metallurgy, which has been 
too much and too long neglected; a few doz- 
en metallic alloys are all that science (or ac- 
cident) has contributed to the useful arts, 
while the chemical metallic combinations are 
numbered by thousands. Modern science 
is yearly adding to the list of known metals, 
but how few useful combinations of them are 
ever heard of. Were one -tenth of the thought, 
labor, and mone/ spent upon alloys, that is 
spent upon useless mechanical invention, we 
doubt not but that very surprising and 
useful results would be brought to light. No 
scientific reasoning on the resultant of the 
combination of two metals, can prove truth- 
ful ; nothing short of actual experiment can 
be relied upon. Who would have dreamed 
that the combination of two metals as soft as 
tin and copper, would produce so hard a com- 
pound as speculum metal ? And it is as sur- 
prising that the sweet and limpid glycerine, 
combined with nitric acid, should form that 
truly fearful combination — Nitro-glycerine, 
We hope to see the day when the com- 
binations of metals with metals shall be 
as fully developed as are now their 
combinations with the non-metallic elements. 
We shall hereafter speak further on this sub- 
ject of alloys. 

The combinations of the simple metals 
with the non-metallic simples, form the basis 
of compounds which are infinite, and in most 
of these combinations the metallic character- 
istics are lost sight of. In all the oxides, 
chlorides, sulphides, etc., etc., the metallic 
peculiarities disappear, anel with many of the 
compounds the highest chemical skill is re- 
quired to eliminate the metallic base. It is 
this tenacity with which they cling to their 
affinities that renders their separation so dif- 
ficult; and it is only by the persevering sk 11 
of the chemist that the new metals are being 
slowly but constantly divorced from their 
firm attachments. 



J5@°- Good oil is essential to the correc 
performance of a watch, and parties using 
Kelley's oil will require to exercise caution in 
its purchase, as a spurious article has been 
thrown on the market. 



AMERICAN HOROLOGICAL JOURNAL. 



163 



TRAVELLING OPTICIANS. 



Editor Horological Journal: 

There is no profession or branch of trade 
that can claim freedom from charlatans and 
impostors, and outside of the medical profes- 
sion I know of none that feel the baneful in- 
fluence of these unprincipled scoundrels more 
than do the jewellers and opticians. It is not 
to be supposed that charlatanry can be put 
down as long as unprincipled men and a 
gullible public exist ; but if those who can, 
will exert themselves in the proper direction 
when the occasion offers, they can most ef- 
fectually bring some of these impostors to 
grief. I wish to direct the attention of your 
readers to a class of men who travel about 
the country calling themselves "Opticians." 
As nearly every watchmaker or jeweller who 
has a store keeps spectacles, even if he is not 
a regular optician, they will undoubtedly be 
interested in this subject to a greater or less 
extent. I will first state that it is a well 
established fact that no physician of character 
or standing in his profession, or the commu- 
nity in which he lives, ever travels about the 
country seeking patients ; the moment that 
he does so, he proves his incapacity to do what 
he claims that he can and will do. If any 
one of these travelling doctors could do what 
they my they can do, instead of seeking pati- 
ents first in one place then another, they would 
have a thousand times more than they could 
attend to even if they were located on the 
top of one of the Rocky Mountains. Now, 
the science of medicine and that of optics are 
closely allied, and all these opticians claim 
to cure diseases of the e} r e; i. e., they are ocu- 
lists as well as opticians, or as some of them 
advertise themselves " Optical Oculists." And 
the remarks that I have made about travel- 
ling physicians are equally applicable to 
travelling " Oculists." 

An Oculist is one who understands the 
anatomy of the eye, can determine the charac- 
ter of any abnormal .condition of the same, 
either congenital or that caused by accident 
or disease, and can cure such cases as are 
curable, or devise means to counteract some 
of these abnormal conditions to a greater or 
less extent. An Optician is one who makes or 
sells optical goods, and who ought to have a 



pretty thorough knowledge of the science of 
optics, especially if he expects to succeed in 
his business, or do justice to his customers. 
Of course an oculist must fully understand 
the science of optics, the laws of the refraction 
and reflection of light. Now, every man who 
keeps spectacles for sale ought to know some- 
thing about optics, so as to be able to select 
such glasses as are suitable, and of the proper 
focus, for the great majority of his customers; 
for very few men can select the proper glasses 
for themselves without the aid of some one 
who is competent to assist them. Now, if 
every watchmaker throughout the country 
would only inform himself on this subject, he 
would not only be able to do justice to his 
customers, but could protect them from the 
travelling so-called opticians. I have never 
yet heard of a single travelling optician who 
was anything but a humbug. They are usu- 
ally men who have a great deal of assurance, 
and are what are called " sharp fellows." 
They make use of a great many high-sound- 
ing words, talk very learnedly about the pecu- 
liarities of the eye, and create the impression 
upon the minds of those who are ignorant of 
the subject that this particular " Professor " 
is the only man in the world, or at least the 
only one that travels (they all denounce each 
other as humbugs) who is qualified to select 
spectacles for the afflicted, and in fact the only 
man who has spectacles that are fit to be 
worn, which are " adjusted to the eye upon 
principles entirely his own, which have never 
been known to fail." They usually claim to 
have factories in Europe, or are professors 
in some eye hospital, or something of the 
kind, and all claim to make their own spec- 
tacles ; and it seems the more and bigger 
lies they can tell, the more readily they are 
believed. 

I have never yet failed to run these chaps 
off when they have come into my section. 
As soon as one of these " Professors" arrives 
he usually advertises very extensively. I do 
the same, and state that I will test spectacles 
for anybody free of charge (as the spectacles 
sold by these fellows, are nearly always sold for 
pebbles, and are in reality nothing but glass). 
I also give the price of pebble and other 
spectacles in steel, silver, and gold frames — 
what they are sold for by resident opticians. 



164 



AMERICAN HOROLOGICAL JOURNAL. 



etc. I make my advertisement as conspicuous 
as the " celebrated opticians," and tell nothing 
but the truth, and put in plenty of local. 
They cannot stand exposure, and if the at- 
tention of the public is only called to these 
chaps, by some one who can show them up, 
their occupation is gone in that place. Every 
one of these men that I have exposed, has 
threatened to whip me (sol have been told); 
but they never tried it on. 

The smartest and sharpest travelling optic- 
ian that I ever saw paid us a visit not long ago. 
He came with four or five large trunks, and a 
very large stock of spectacles, and gave out 
that he would remain a month. That was 
the length of time he staid in each place 
that he visited, and he would usually take in 
from $2,000 to $6,000 in that short time. As 
he charged from $10.00 to $15.00 a pair for 
steel frame spectacles, and $30.00 a pair for 
gold frames, the profits can be easily calcula- 
ted. He secured the parlor of the hotel for 
his show and salesroom, displayed his goods 
to the best advantage, had some large pieces 
of glass, also of rock crystal, and his optomi- 
ter, etc., all arranged to attract attention. 
He then procured a carriage, and personally 
called to see the principal doctors and preach- 
ers, and gave each a pressing invitation to 
call and see his spectacles, instruments, etc. ; 
at a certain hour they did so, and the" Prof." 
gave each a pair of spectacles, explaining the 
marvellous good qualities of the same, and 
denouncing all others to be injurious to the 
eye, — exhibited a diploma that he claimed to 
have received from some medical college in 
Europe, spoke very learnedly and fluently of 
the different diseases of the eye, and then 
requested these gentlemen to sign some of 
his printed certificates, which went on to say, 
that " Prof. wa6 the most scientific opti- 
cian and oculist that they had ever seen ; 
that he made his spectacles on truly scientific 
principles, so much better than any others 
they had ever seen, "etc., etc. In every place 
but this the M. D.s and D. D.s would sign 
the certificates, which the "Prof." would put 
in the paper as part of his advertisement. 
This would be done before he would offer a 
single pair for sale. Now when the commu- 
nity saw the names of these learned and good 
men, whom they knew to be honest gentle- 



men, appended to these certificates, the effect 
would be magical ; everybody who used 
spectacles fairly flocked to this man's room, 
and exchanged their " ducats " for spectacles. 
Now you will ask, why did these physicians 
and others sign these certificates if the man 
was a humbug? Simply because there is 
not one physician in fifty that knows com- 
paratively anything about the eye. If they 
have a patient who is afflicted with some 
disease of that organ, which is seldom the 
case, other than some simple case of inflam- 
mation or something of that kind, they send 
him to some one who makes a specialty of 
that class of diseases, and consequently he 
signs the cei'tificate through ignorance ; or 
in other words he is imposed upon. I had 
seen this man's advertisement before he came 
here, and as soon as he came I called the 
attention of our physioians to what other 
physicians had certified to. They immedi- 
ately saw the point, and said that they could 
not see how any Dr. could certify that the 
"Prof." made his own spectacles, and upon 
scientific principles, etc., when they had not 
seen him make them ; in other words, they 
could not vouch for the accuracy of what a 
perfect stranger would say about himself, 
and more especially when he did not have a 
single certificate from any oculist or optician 
in this country, which explains why the 
physicians of this place did not sign the certi- 
ficates. They called on the gentleman with 
their eyes open. The next morning my ad- 
vertisement appeared, giving the price of 
spectacles, etc., etc. ; that day the "Prof." 
said that he "did not think he had been 
treated properly, and as the place was so 
small he would leave ; but would be back 
again soon." Now if he could have met with 
the same reception in every city that he 
visited, his career would have been short ; 
for he did not sell a single pair of spectacles 
during his stay here. There is no doubt but 
what this man would have swindled our 
community out of at least $3,000, if I had 
held my tongue. Now let every watchmaker 
devote some of his spare time to the study of 
optics, and then get " "Wells on Long, Short 
and Weak Sight," published by Lindsay & 
Blackiston, Philadelphia. Jas. Fkickeb. 
Amsricus, Ga. 



AMERICAN HOROLOGICAL JOURNAL. 



165 



LIGHT* 



NUMBER TWO. 



THE REFLECTION OF LIGHT ( CATOPTRICS ) PLANE 

MIRRORS. 

When light passes from one optical medium 
to another, a portion of it is always turned 
back or reflected. 

Light is regularly reflected by a polished 
surface ; but if the surface be not polished 
the light is irregularly reflected or scattered. 
Thus a piece of ordinary drawing-paper will 
scatter a beam of light that falls upon it so 
as to illuminate a room. A plane mirror 
receiving the sunbeam will reflect it in a 
definite direction, and illuminate intensely a 
small portion of the room. If the polish of 
the mirror were perfect it would be invisible — 
we should simply see in it the images of 
other objects ; if the room were without dust 
particles, the beam passing through the air 
would also be invisible. It is the light scat- 
tered by the mirror and by the particles sus- 
pended in the air which renders them visible. 

A ray of light striking as a perpendicular 
against a reflecting surface is reflected back 
along the perpendicular ; it simply retraces 
its own course. If it strike the surface 
obliquely, it is reflected obliquely. Draw a 
perpendicular to the surface at the point 
where the ray strikes it ; the angle enclosed 
between the direct ray and this perpendicular 
is called the angle of incidence. The angle 
enclosed by the reflected ray and the perpen- 
dicular is called the angle of reflection. It is 
a fundamental law of optics that the angle of 
incidence is equal to the angle of reflection. 

VERIFICATION OF THE LAW OF REFLECTION. 

Fill a basin with water to the brim, the 
water being blackened by a little ink. Let a 
Bmall plummet — a small lead bullet, for exam- 
ple — suspended by a thread, hang into the 
water. The water is to be our horizontal 
mirror, and the plumb-line our perpendicu- 
lar. Let the plummet hang from the centre 
of a horizontal scale, with inches marked 
upon it right and left from the point of sus- 
pension, which is to be the zero of the scale. 
A lighted candle is to be placed on one side 
of the plumb-line, the observer's eye being at 
the other. 



* Extracts from Prof. Tyndall's lectures on Light 



The question to be solved is this : — How is 
the ray which strikes the liquid surface at the 
foot of the plumb-line reflected ? Moving the 
candle along the scale, so that the tip of its 
flame shall stand opposite different numbers, 
it is found that, to see the reflected tip of the 
flame in the direction of the fool of the plumb- 
line, the line of vision must cut the scale as 
far on the one side of that line as the candle 
is on the other. In other words, the ray 
reflected from the foot of the perpendicular 
cuts the scale accurately at the candle's dis- 
tance on the other side of the perpendioular. 
From this it immediately follows that the 
angle of incidence is equal to the angle of 
reflection. 

With an artificial horizon of this kind, and 
employing a theodolite to take the necessary 
angles, the law has been established with the 
most rigid accuracy. The angle of elevation 
to a star being taken by the instrument, the 
telescope is then pointed downwards to the 
image of the star reflected from the artificial 
horizon. It is always found that the direct 
and reflected rays enclose equal angles with 
the horizontal axis of the telescope, the 
reflected ray "Jbeing as far below the hor- 
izontal axis as the direct ray is above 
it. On account of the star's distance the ray 
which strikes the reflecting surface is parallel 
with the ray which reaches the telescope 
directly, and from this follows, by a brief but 
rigid demonstration, the law above enun- 
ciated. 

The path described by the direct and 
reflected rays is the shortest possible. When 
the reflecting surface is roughened, rays from 
different pofnts, more or less distant from 
each other, reach the eye. Thus, a breeze 
crisping the surface of the Thames or Ser- 
pentine sends to the eye, instead of single 
images of the lamps upon their margin, pil- 
lars of light. Blowing upon our basin of 
water, we also convert the reflected light of 
our candle into a luminous column. Light is 
reflected with different energy by different 
substances. At a perpendicular incidence, 
only 18 rays out of every 1000 are reflected 
by water, 25 rays per 1000 by glass, while 666 
per 1000 are reflected by mercury. 

When the rays strike obliquely, a greater 
amount of light than that stated in 60 is . 



166 



AMERICAN HOROLOGICAL JOURNAL. 



reflected by water and glass. Thus, at an 
incidence of 40°, water reflects 22 rays ; at 
60°, 65 rays ; at 80°, 333 rays ; and at 89i° 
(almost grazing the surface) it reflects 721 
rays out of every 1000. This is as much as 
mercury reflects at the same incidence. The 
augmentation of the light reflected as the ob- 
liquity of incidence is increased, may be illus- 
trated by our basin of water. Hold the can- 
dle so that its rays enclose a large angle with 
the liquid surface, and notice the brightness 
of its -image. Lower both the candle and 
the eye until the direct and reflected rays as 
nearly as possible graze s the liquid surface ; 
the image of the flame is now much brighter 
than before. 

Reflection from Looking-glasses. — Various 
instructive experiments with a looking-glass 
may here be performed and understood. 

Note first when a candle is placed between 
the glass and the eye, so that a liue from the 
eye through the candle is perpendicular to 
the glass, that one well-defined image of tl e 
candle only is seen. Let the eye now be moved 
so as to receive an oblique reflection ; the 
image is no longer single, a series of images 
at first partially overlapping each other being 
seen. By rendering the incidence sufficiently 
oblique, these images, if tbe glass be suffi- 
ciently thick, may be completely separated 
from each other. 

The first image of the series arises from 
the reflection of the light from the anterior 
surface of the glass. The second image, which 
is usually much the brightest, arises from re- 
flection at the silvered surface of tbe glass. 
At lai'ge incidences, as we have just learned, 
metallic reflection far transcends that from 
glass. The other images of the series are 
produced by the reverberation of the light 
from surface to surface of the glass. At 
every return from the silvered surface a por- 
tion of the light quits the glass and reaches 
the eye, forming an image ; a portion is also 
sent back to the silvered surface, where it is 
again reflected. Part of this reflected beam 
also reaches the eye and yields another 
image. This process continues; the quantity 
of light reaching the eye growing gradually 
less, and, as a consequence, the successive 
images growing dimmer, until finally they 
become too dim to be visible. 



A very instructive experiment illustrative 
of the augmentation of the reflection from 
glass, through augmented obliquity, may here 
be made. Causing the candle and the eye to 
approach the looking-glass, the first ima~e 
becomes gradually brighter ; and you end by 
rendering the image reflected from the glass 
brighter, more luminous, than that reflected 
from the metal. Irregularities in the reflec- 
tion from looking-glasses often show them- 
selves ; but with a good glass — and there are 
few 7 glasses so defective as not to possess, at 
all events, some good portions — the succes- 
sion of images is that here indicated. 

Position and Character of Images in Plane 
Mirrors. — The image in a plane mirror ap- 
pears as far behind the mirror as the object 
is in front of it. This follows immediately 
from the law which announces the equality 
of the angles of incidence and reflection. 
Draw a line representing the section of a 
plane mirror ; place a point in front L of it. 
Rays issue from that point, are reflected from 
the mirror and strike the pupil of the eye. 
The pupil is the base of a cone of such rays. 
Produce the rays backward ; they will inter- 
sect behind the mkror, and the point will 
be seen as if it existed at the place of inter- 
section. The place of intersection is easily 
proved to be as far behind the mirror as the 
point is in front of it. 

Exercises in determining the positions of 
images in a plane mirror, the positions of the 
objects being given, are here desirable. The 
image is always found by simply letting fall a 
perpendicular from each point of the object, 
and producing it behind the mirror, so as to 
make the part behind equal to the part 
in front. Yv'e thus learn that the image is of 
the same size and shape as the object, agree- 
ing with it in all respects save one — the 
image is a lateral inversion of the object. t 

This inversion enables us, by means of 
a mirror, to read writing written backward, 
as if it were written in the usual way. Com- 
positors arrange their type in this backward 
fashion, the type being reversed by the pro- 
cess of printing. A looking-glass enables us 
to read the type as the printed page. 

Lateral inversion comes into play whenjwe 
look at our own faces in a glass. The right 
cheek of the object, for example, is the left 



AMERICAN HOROLOGICAL JOURNAL. 



167 



cheek of the image ; the right hand of the 
object the left hand of the image, etc. The 
hah* parted on the left in the object is seen 
parted to the right of the image, etc. A plane 
mirror half the height of an object gives an 
image which embraces the whole height. 
This is readily deduced from what has gone 
before. If a plane mirror be caused to move 
parallel with itself, the motion of an image 
in the mirror moves with twice its rapidity. 
The same is true of a rotating mirror ; when 
a plane mirror is caused to rotate, the angle 
described by the image is twice that described 
by the mirror. In a mirror inclined at an 
angle of 45° to the horizon, the image of an 
erect object appears horizontal, while the 
image of a horizontal object appears erect. 
An. object placed between two mirrors? 
enclosing an angle yields a number of images 
depending upon the angle enclosed by the 
mirrors. The smaller the angle, the greater 
is the number of images. To find the num- 
ber of images, divide 360° by the number of 
degrees in the angle enclosed by the two mir- 
rors; the quotient, if a whole number, will be 
the number of images, plus one, or it will 
i aclude the images and the object. The con- 
struction of the kaleidoscope depends on this. 
When the angle becomes — in other words, 
when the mirrors are parallel — the number 
of images is infinite. Practically, however, 
we see between parallel mirrors a long suc- 
cession of images, which become gradually 
feebler, and finally cease to be sensible to the 
eye. 

REFLECTION FROM CURVED SURFACES ; CONCAVE 
MIRRORS. 

It has been already stated and illustrated 
that light moves in straight lines, which 
receive the name of rays. Such rays may be 
either divergent, parallel, or convergent. 
Rays issuing from terrestrial points are ne- 
cessarily divergent. Rays from the eun or 
stars are, in consequence of the immense dis- 
tances of these objects, sensibly parallel. By 
suitably reflecting them, we can render the 
rays from terrestrial sources either parallel or 
convergent. This is done by means of concave 
mirrors. In its reflection from such mirrors, 
light obeys the law already enunciated for 
plane mirrors. The angle of incidence is 
equal to the angle of reflection. 



Let M N be a very small portion of the 
circumference of a circle with its centre at O. 
Let the line a x, passing through the centre, 
cut the arc M N into two equal parts at a. 
Then imagine the curve M N twirled round 
a a: as a fixed axis ; the curve would describe 
part of a spherical surface. Suppose the sur- 
face turned towards x to be silvered over, 
we should then have a concave spherical 
reflector ; and we have now to understand 
the action of this reflector upon light. 




The line a xis the principal axis of the mir- 
ror. All rays from a point placed at the centre 
O strike the surface of the mirror as perpen- 
diculars, and after reflection return to O. A 
luminous point placed on the axis beyond O, 
say at x, throws a divergent cone of rays 
upon the mirror. These rays are rendered 
convergent on reflection, and they intersect 
each other at some point on the axis between 
the centre and the mirror. In every case 
the direct and the reflected rays (x m and m. 
x, for example) enclose equal angles with tie 
radius (Obi) drawn to the point of incidence. 
Supposing x to be exceedingly distant, say as 
far away as the sun from the small mirror— 
or, more correctly, supposing it to be infi- 
nitely distant, — then the rays falling upon the 
mirror will be parallel. After reflection such 
rays intersect each other, at a point midway 
between the mirror and its centre. This point, 
which is marked F in the figure, is the princi- 
pal focus of the mirror ; that is to say, the 
principal focus is the focus of parallel rays. 
The distance between the surface of the mir- 
ror and its principal focus is called the focal 
distance. 

In optics, the position of an object and of 
its image are always exchangeable. If a lumi- 
nous point be placed in the principal focus, 
the rays from it will, after reflection, be par- 
allel. If the point be placed anywhere between 
the principal focus and the centre 0, the ray« 



168 



AMERICAN HOROLOGICAL JOURNAL. 



after reflection will cut the axis at some point 
beyond the centre. If the point be placed 
between the principal focus F and the mirror, 
the rays after reflection will be divergent — 
they will not intersect at all — there will be no 
real focus. But if these divergent rays be 
produced backwards, they will intersect 
behind the mirror, and form there what is 
called a virtual or imaginary focus. 



o- 



ANSWEBS TO CORRESPONDENTS. 



A. F. T. — There is no fixed place for the 
compensation on the pendulum described on 
page 112, Vol. II., Hoeological Journal. 
The object of the set screw in the collet C is 
to allow tbe compensation to be placed in 
such a position on the rod as may be found 
proper by experiments; and the nuts travers- 
ing the rods B are used to adjust it more 
accurately than can be done by moving the 
collet. Fasten the collet at about one-third 
tbe length of the rod from the lower end and 
try it in tbe clock ; if the clock gains as the 
temperature decreases, lower the compensa- 
tion ball, or raise it if tbe clock loses. Be 
careful to alter it according to the rate of the 
clock ; if the rate is large alter it by using the 
set screw in the collet, but if the rate is small 
use the nuts on the rods. 

AMERICAN IIOHOLOGrlCAL JOURNAL, 

PUBLISHED MONTHLY BY 

•G.^B. MILLER, 

!i:i'J Broadway, JV. F., 
At $'2.50 per Year, payable in advance. 

A limited number of Advertisements connected 
rvith the Trade, and from reliable Houses, will be 
received. 

j&tsg~ Mr. J. Herrmann, 21 Northampton 
Square, E. C, London, is our authorized Agent 
for Great Britain. 
All communications should be addressed, 
G. B. MILLER, 
P. 0. Box G715, New York. 



EQUATION OF TIME TABLE. 



GREENWICH MEAN TIME. 



For January, 1871. 



Su. 

M. 

Tu 

W. 

Th. 

I'ri 

Sat 

Su. 

M.. 

Tu. 

W. 

Th. 

Ii-I 

Sat 

Su. 

M.. 

Tu. 

W. 

Th. 

Fri. 

Sal 

Su. 

M.. 

Tu. 

W. 

Th. 

Fri. 

Sal 

Su. 

M. 

To. 



Day 

of 
Mon. 



Sidereal 
Time 
of 
the Semi- 
diameter 
Passing 

the 
Meridian. 



Equation 

of 

Time to be 

Added to 

Apparent 

Time. 



8. 

71.09 
71.04 
70.99 
70 94 
70.88 
70.82 
70.75 
70.68 
70.61 
70.54 
70.46 
70.38 
70.30 
70.21 
70.12 
70.02 
69 92 
69.82 
69.72 
69.62 
69 52 
69.41 
69 30 
69.19 
69.08 
68.97 
68.86 
68 75 
68.63 
68.51 
6* 40 



3 44.73 

4 12.92 

4 40 74 

5 8.17 

5 35.18 

6 1.73 
6 27.81 

6 53.42 

7 18.52 

7 43.07 

8 7.06 
8 30.49 

8 53.32 

9 15.52 
9 37.09 
9 58.03 

10 18.27 
10 37.81 

10 56.64 

11 14.74 
11 32.08 

11 48.66 

12 4.47 
12 19.48 
12 33.68 
12 47.06 

12 59.61 

13 11 33 
13 22.20 
13 32.24 
13 41.44 



Equation 

of 

Time to be 

Subtracted 

from 
Mean Time. 





Sidereal 




Time 


Diff. 


or 


for 


Right 


One 


Ascension 


Hour. 


of 




Mean Sun. 



44 65 
12.83 
40.65 

8.07 
35 08 

1.62 
27.70 
53.30 
18.40 
42.94 
8 6.93 
8 30.35 

8 53.18 

9 15 38 
9 36.95 
9 57.89 

10 18.13 
10 37.67 

10 56.50 

11 14.60 
11 31 94 

11 48 52 

12 4.34 
12 19.35 
12 33.56 
12 46.94 

12 59.49 

13 11.22 
13 22.10 
13 32.15 
13 41.35 



1.182 

1.167 

1.151 

1.134 

1.116 

1.097 

1.077 

1.057 

1.035 

1.012 

0.988 

0.964 

0.939 

0.913 

0.886 

0.858 

0.829 

0.800 

771 

0.740 

0.708 

0.676 

0.643 

0.610 

0.576 

0.541 

0.506 

0.471 

0.436 

0.401 

0.366 



H. M. S. 

18 42 46.98 
18 46 43.54 
18 50 40.10 
18 "54 36.66 

18 58 33.21 

19 2 29.77 
19 6 26.33 
19 10 22.89 
19 14 19.44 
19 18 16.00 
19 22 12.56 
19 26 9.12 
19 30 5.67 
19 34 2.23 
19 37 58.79 
19 41 55.34 
19 45 51.90 
19 49 48.46 
19 53 45.02 

19 57 41.57 

20 138.13 
20 5 34.69 
20 9 31.24 
20 13 27.80 
20 17 24.35 
20 21 20.91 
20 25 17.47 
20 29 14.02 
20 33 10.58 
20 37 7.13 
20 41 3.69 



CHARLES SPIRO, 

3R ! atrIi mul (Shnmamrtw Pate, 

No. _33 John Street, 
Corner Nassau, NEW Y0BK. 

Hair Springe, Jewela and Wheels Made to Order. 



Mean time of the Semidiameter passing may be found by sub- 
tracting 0.19 s. from tbe sidereal time. 

The Semidiameter for mean neon may bo assumed the same as 
that for apparent noon. 

PHASES OF THE MOON. 

D. H. M. 

© Full Moon 6 9 23.6 

( Last Quarter 13 18 57.0 

O New Moon 20 12 318 

) FirstQuarter 28 1 14.4 

D.. H. 

( Apogee 1 16.5 

( Perigee t . . 17 18 2 

( Apogee. 19 12.0 

O I II 

Latitude of Harvard Observatory 42 22 48 . 1 

H. m. s. 

Long. Harvard Observatory 4 44 29 . 05 

New York City Hall 4 56 0.15 

Savannah Exchange 5 24 20 572 

Hudson, Ohio .. _ 5 25 43.20 

Cincinnati Observatory 5 37 58.062 

Point Conception 8 142.64 







APPARENT 


APPARENT 


MERID. 






R. ASCENSION. 


DECLINATION. 


PASSAGE. 




D. 


H. M. S. 


o ' 1 


H. M. 




1 


19 12 0.90.. 


..-23 20 30.3.. 


... 29.3 


Jupiter.. . 


. 1 


5 11 58.57.. 


.. + 22 33 6.6.. 


...10 27.3 


Saturn. . 


. 1 


18 8 56.13.. 


.. -22 36 49.7.. 


...23 22.8 



AMERICAN 



Horolosical Journal. 



Vol. H. 



NEW YORK, FEBRUARY, 1871. 



No. 8. 



CONTENTS. 

The Pendulum, 169 

Heat, 175 

Measuring Haiti-Springs 179 

Abstract of Rates of Chronometers, . . . 180 

Meials and Allots, 184 

Hints to Repairers 186 

Light, i ..... .188 

Answers to Correspondents, 191 

Equation of Time Table, 192 

* t * Address all communications for Horological 
Journal io G. B. Miller, P. 0. Box 6715, New York 
City. Publication Office 229 Broadway, Room 19. 



Sg§~ The second instalment of Mr. Gross- 
mann's essay failed to reach us in time for 
this number. Of course, at this season of the 
year, ocean steamers are liable to delays, and 
we must accept the inevitable with the best 
grace possible. Probably before the close of 
the month we shall receive the entire work, 
and then there will be no further interrup- 
tions. 

In the present number we also commence 
an original essay on the Pendulum as applied 
to the Measurement of Time, to which we 
invite the careful attention of our readers. 
In the series of articles on Heat, which will 
be closed in the April issue, will be collected 
a mass of facts which will prove of value to 
every workman, no matter what his experi- 
ence may have been. 

Having given some extracts from Prof. 
Tyndall's lecture on Light, bringing the sub- 
ject down to the consideration of lenses, next 
month we shall describe the method of grind- 
ing, as practised in this country, together 
with some remarks on the proper selection of 
lenses for the eye. Several " Answers " are 
crowded out this month. In reply to a query 
from A. F. T., we propose to give an article 
on Pinions in a short time. 



[Entered according to Act of Congress, by G. B. Miller, In the 
office of the Librarian of Congress at Washington.] 

THE PENDULUM 

AS APPLIED TO THE 

MEASUREMENT OF TIME. 



NUMBER ONE. 



INTRODUCTION TERRESTRIAL GRAVITY. 

Of the many machines or instruments of 
precision that are in general use for private 
or for public purposes, there are probably 
none where so much misconception exists, or 
lack of knowledge of first principles is dis- 
played, as in those instruments commonly 
constructed for the measurement of time; 
and all those acquainted with the subject, and 
who have had an opportunity of observing, 
can confirm that this misconception or ignor- 
ance is not confined to the general public, 
but is developed in a large degree throughout 
the trade, or among those tradesmen whose 
business it is to repair or sell such instru- 
ments. If we take the subject of the pen- 
dulum for instance, it is surprising how 
many there are who, in the exercise of their 
inventive faculties to provide a means of over- 
coming the difficult question of compensation, 
exhibit so much want of fundamental knowl- 
edge of the subject, and often create greater 
errors than they suppose to have cured. The 
periodical literature of the day frequently 
contains diagrams and correspondence on the 
question which abundantly prove this asset 
tion. 

Perhaps, on the part of the workmen, this 
may be in some measure a result of the grow- 
ing tendency of the age to Concentrate special 
manufactures in certain localities, and also to 
the extensive system of subdividing labor, 
now generally adopted ; although productive 
of such good results, unquestionably it \ laces 
the young watch and clock makers under 
greater difficulties to find suitable opportu- 



170 



AMERICAN HOEOLOGICAL JOURNAL. 



nities ,to master all the intricacies of their 
profession than was experienced a generation 
ago. 

The scientific, or, more correctly, the 
pseudo-scientific world is also teeming with 
misconceptions on this subject. In a work 
newly published on the chemical forces, the 
author, talking about the Harrison pendulum, 
says: "This pendulum gained the reward of 
£20,000, offered by the British Government 
for a pendulum that did not lose more than 
the fraction of a second in a year, and enabled 
the longitude to be determined within thirty 
miles." It is seldom one sees so many false 
ideas condensed into so few lines. Probably 
this statement had its origin in the fact that 
about the end of the last century Mr. Harris- 
son received such a reward for a portable 
time-keeper that could be used on shipboard 
for the purpose of finding a ship's longitude 
on the ocean to within thirty miles; but a time- 
keeper that would not vary more than the frac- 
tion of a second in a year would enable the 
longitude to be determined at any time to the 
small fraction of a mile instead of thirty miles. 
Our nautical friends would find a pendulum 
ill suited for finding longitude at sea, and if 
writers on any subject connected with chem- 
ical forces, or chemical physics, and many 
other persons besides, were less credulous, 
and reflected a little, they have ability enough 
noon to discover that such a result was at that 
time, and even at the present day, altogether 
beyond the power of human skill to accom- 
plish. » In order thet such a result should be 
reached, the pendulum — assuming it to be a 
seconds one — would require to vibrate pre- 
cisely 31,535,099 and a fraction times in 365 
days; and the fraction of a second that is lost 
must be subtracted in an equal ratio from the 
31,536,000 seconds that make up the year, 
regularly and in equal proportion, from sec- 
ond to second, from hour to hour, and from 
day to day, during the 365 days that consti- 
tute our year, and that, too, amidst all the 
physical changes that are continually going 
on within and around the clock, although it 
may be placed in the best situation possible 
to be obtained. 

Time-keepers may be considered to consist 
of two distinct orders. Those that are port- 
able, like watches, for example, that have 



their motion imparted to them by a spring, 
and regulated by a balance and spring, or, as 
it were, impelled and regulated by an opposi- 
tion of artificial forces; and those that are 
stationary, like clocks, and are propelled by 
weights, and regulated by the oscillations of a 
pendulum, or, in fact, regulated by the natural 
force of gravitation. To this question of meas- 
uring time by the natural force of gravitation, 
we propose to devote our attention, and in- 
vestigate the many questions that bear upon 
the subject, from the simple or ideal pendulum 
to the compound and Compensated one, and 
the difficulties to be overcome in obtaining a 
perfect compensation. Although a pendulous 
body, by the isochronism of its oscillations, 
furnishes a means of dividing time into equal 
portions, it could obviously be of little use 
until some method was devised of continuing 
the motion of the pendulum, and registrating 
the number of its vibrations. This mechan- 
ism, technically known as the escapement, we 
propose also to consider in the relation it 
bears to the pendulum itself, and illustrate 
the effects that the various forms of escape- 
ments have on the isochronal properties of the 
pendulum, and point out where their action 
in some cases partly serves for compensation 
in a plain pendulum, and in other cases tends 
to make the question of adjusting a compen- 
sated one a matter of contradiction and diffi- 
culty. Although it be our object to discuss 
fully the intricate questions connected with 
the highest class of clock-work, we will omit, 
at least for the present, taking any notice of 
the various systems of striking the hours, or 
the multitudinous automatic contrivances 
sometimes attached to clocks for various pur- 
poses, which, although they often show great 
ingenuity of construction, bear no relation to 
the principle that governs the motion of the 
clock itself, but in all cases tend to destroy 
the accuracy of its performance, except where 
Bond's escapement is used. 

The pendulum is a most important instru- 
ment to the scientific world. It is applied to 
determine the relative force of gravity at 
different points on the earth's surface, and to 
determine its shape. It is also from the 
pendulum that the British standard yard 
measure is deduced ; but its most important 
application has been to the measurement of 



AMERICAN HOROLOGICAL JOURNAL. 



171 



time. It is a question of some doubt as to 
who was the exact individual that first con- 
ceived the idea to measure time by the oscil- 
lations of a pendulum. The Italians claim 
the honor for one of their countrymen, but 
there are records to show that long before 
the days of Galileo the ancient Asiatic 
astronomers measured the duration of tran- 
sits and eclipses by counting the vibrations 
of a pendulum ; and to show that this was 
practicable, we notice that in modern times 
European and American astronomers have 
used pendulums in this manner for certain 
temporary operations in the field. Prof. 
Winloek, of Harvard College, Cambridge, had 
a pendulum applied without any clock-work 
attached to it, to break the circuit of the 
electrical apparatus that was fitted up in 
Kentucky to observe the duration of the total 
eclipse of the sun that was visible in some 
parts of North America in 1869 ; and. if we 
are not mistaken, the same was used by the 
party sent to Spain by the United States 
Government, to observe the total eclipse of 
the sun lately seen from the south of Europe. 
Galileo was the first who formally an- 
nounced, in his work on mechanics and mo- 
tion, which was published in the year 1639. 
the isochronal property of oscillating bodits 
suspended by strings of the same length ; 
and it has been said that he actually applied 
a pendulum to a clock, for the purpose ol 
observing eclipses and determining longi- 
tudes ; but as there is no proof existing to 
corroborate the assertion, the fact may be 
considered doubtful. Sanctorius, in his Com- 
mentary on Avicenna, describes an instrument 
to which he had applied a pendulum in 1612. 
Richard Harris is said to have constructed, 
in 1611, a pendulum clock in London for St. 
Paul's Church, Covent Garden. Vincenzo 
Galilei, a son of Galileo, is stated, on the 
authority of the Academy del Cimenlo, to have 
applied the pendulum in 1649. It was ap- 
plied by Huyghens in 1656, and by Hooke, for 
whom the invention has been claimed, about 
1670. But to whomsoever the merit may 
belong of having first made the application, 
Huyghens is unquestionably the first that, in 
his Hbrologium Oscillatoreum, explained the 
theory of the pendulum ; and on this ac- 
count, perhaps, the invention of the pen- 



dulum clock has been usually ascribed to 
him. After demonstrating the true theory of 
the pendulum, Huyghens's next object was 
to devise a means of causing a pendulum 
to vibrate in such a manner that its centre 
of oscillation would describe the arc of a 
C3 r cloid. The diagram before us exhibits a 




cycloidal and a circular curve, and the point 
to the right represents the centre of oscilla- 
tion of an imaginary pendulum. The re- 
sult Huyghens sought was, that, after this 
point had passed the perpendicular line, it 
should be gradually raised up in a certain 
degree as it ascended the circular curve ; yet 
although this cycloidal curve is the true 
curvo a simple pendulum should describe in 
its oscillations, to make them isochronous it 
it has been found impossible to carry it out 
in practice with any beneficial result. 

Many of our readers will have noticed old 
clocks, mostly in buhl cases and of French 
construction, having the verge and crown 
wheel escapement, and a 
very light pendulum sus- 
pended from a thread ; on 
each side of which thread 
are placed two pieces of 
curved brass, which repre- 
sent part of the evolute of 
a cycloid. As the pendulum 
moves, the thread touches 
the brass curves and raises 
the ball, or, in fact, it raises 
the whole of the pendulum 
up, and approximately causes the ce ^tre of 
oscillation to describe a cycloid. This was 
the plan by which Huyghens sought to obvi- 
ate one of the irregularities in clocks having 
large vibrations ; still, the varying impulse 
the pendulum receives on its descent, im- 
parted to it from the crown wheel through 
the verge, and the variation of resistance it 
has to encounter from the recoil of the crown 
wheel on its ascent, makes the cycloidal curve 
of no practical value could it be carried out, 




172 



AMERICAN HOROLOGICAL JOURNAL. 



and it is now abandoned by all men of ex- 
perience. 

The pendulums of all clocks of modern con- 
struction do not vibrate in an arc large 
enough to show any perceptible difference 
between the circular and cycloidal curve; yet 
we sometimes meet with a certain class of 
tradesmen whose knowledge of their business 
amounts to nothing more than a foggy super- 
stition, and who are possessed of many secrets 
they carefully treasure up, pretend to adjust 
a pendulum and make it isochronal by manip- 
ulating the pendulum spring, or causing it to 
work between two curves of a peculiar shape, 
and which is nothing more than attempting 
to put in practice what Huyghens abandon- 
ed 200 years ago ; and Huyghens himself 
shows that the error of the hundredth of an 
inch in the form of the cycloidal curve 
described by the pendulum ball, causes 
greater irregularity than if the pendulum de- 
scribed an arc of 10° or 12° on each side of 
the point of rest, in a circle. 

As we go deeper into our subject, we shall 
demonstrate the causes of irregularity in the 
higher class of clocks, whether these irregu- 
larities arise from the varying influences of 
the mechanism or escapement on the pendu- 
lum, or from heat, cold, the varying pressure 
of the atmosphere, magnetic influences, or 
other causes. Some of these we may propose 
a means of obviating, and those that we can- 
not get rid of, we shall, on the principle of 
" what kills also cures," try to use for the 
purpose of obtaining the desired end. 

Although we have stated that the cycloid, 
f o far as it relates to the pendulum, has been 
discarded in practical horology, nevertheless 
a knowledge of this curve, and also of the 
inclined plane, and the laws that govern fall- 
ing bodies, is requisite in order fully to un- 
derstand the question before us, and previous 
to going into the practical part of our sub- 
ject, we shall briefly, and in plain language, 
describe the various phenomena connected 
with each of these subjects. 

Terrestrial Gravity. — Universal experience 
demonstrates that all heavy bodies, when un- 
supported, fall towards the surface of the 
earth. The direction of their motion may be 
ascertained by a plumb line, and it is found to 
be always perpendicular to the level surface 



of the earth, or, more correctly, the surface of 
stagnant water. But the earth is very nearly 
spherical, and a line perpendicular to the 
surface of a sphere must pass through its 
centre; hence the direction of a body moving, 
in consequence of the force of terrestrial grav- 
ity, is toward the centre of the earth. 

As the attraction of the earth acts equally 
and independently on all the particles com- 
posing a body, it is clear that they must all 
fall with equal velocities. It makes no differ- 
ence whether the several particles fall singly, 
or whether they fall compactly together in 
the form of a large or a small body. If ten 
or a hundred leaden balls be disengaged to- 
gether, they will fall at the same time, and if 
they be moulded into one ball of great mag- 
nituele, it will still fall in the same time. 
Hence, all bodies under the influence of grav- 
ity alone, must fall with equal velocities. 

Previous to the time of Galileo, philoso- 
phers maintained that the velocity of a falling 
body was in proportion to its weight ; and 
that if two bodies of unequal weights were let 
fall from an elevation at He sime moment, 
the heavier would reach the ground as much 
sooner than the lighter as its weight exceeded 
it. In other words, a body weighing two 
pounds would fall in half the time that would 
be requrred by a body weighing one pound. 
Galileo, on the contrary, asserted that the 
velocity of a falling body is independent of 
its weight and not affected by it. The dis- 
pute running high, and the opinion of the 
public being generally averse to the views of 
Galileo, he challenged his opponents to test 
the matter by public experiment. The chal- 
lenge was accepted, and the celebrated lean- 
ing tower of Pisa agreed upon as the place of 
trial. In the presence of a large concourse of 
citizens, two balls were selected, one having 
exactly twice the weight of the other. The 
two were then dropped from the summit of 
the tower at the same moment, and, in exact 
accordance with the assertions of Galileo, 
they both struck the ground at the same 
instant. 

As all bodies, when left without support, 
fall from all heights to which they may be 
carried, it may be inferred that gravity acts 
upon them during the whole time of their 
descent, and is therefore a regularly acceler- 



AMERICAN HOROLOGICAL JOURNAL. 



173 



ating force. This might also be inferred 
from the fact, which is easily rendered sensi- 
ble, that bodies which fall from a greater 
height arrive at the earth with a greater 
velocity. If we let an apple fall from off a 
table on the floor, it will not be injured; but, 
if we let the same apple fall from the top 
window of a high house on to the pavement 
beneath, the apple will be smashed to pieces. 
But the best method of showing, experi- 
mentally, that gravity is a uniformly acceler- 
ating force, is by an apparatus known as 
Atwood's machine. This consists of a pulley, 
the axis of which turns on friction rollers, 
and having a groove in its edge to receive a 
string. Over the wheel a fine silken cord is 
stretched, to the ends of which are attached 
two equal weights, A 
and B. In this state 
the weights counter- 
balance each other, and 
no motion ensues; but 
if we add the small 
weight C to the weight 
B, so as to give it a pre- 
ponderance, the loaded 
weight will immediately 
begin to descend. The 
motion which now takes 
place is exactly of the 
same kind with that of 
a body descending 
freely ; and by this 
method, the properties 
of uniformly accelerated motion are experi- 
mently shown to hold true in the descent of 
falling bodies. If the additional load be such 
as will carry the weight to which C is added 
through a space of one foot in the first 
second of time, it will carry it through four 
feet in two seconds, through nine in three 
seconds, and so on. A proof is therefore af- 
forded by this means that terrestrial gravity 
is a uniformly accelerating force. 

There are some familiar facts which seem 
to be opposed to this law. When we let go a 
feather, and a mass of lead, the one floats in 
the air, and the other falls to the ground very 
rapidly. But in this case, the operation of 
gravity is modified by the resistance of the 
air: the feather floats because the air opposes 
its descent, and it cannot overcome the . re- 




sistance offered. But if we place a mass of 
lead and a feather in the exhausted receiver 
of an air-pump, and liberate them at the same 
instant, they will fall in equal periods of time. 

Having ascertained the law according to 
which gravity acts on bodies, the next ques- 
tion is to determine its absolute intensity, or 
the velocity which it communicates to a body 
falling freely in a given time. In the latitude 
of the city of New York, a body falling from 
a height will fall a small fraction less than 16 
feet in the first second of time, three times 
that distance in the second, five times in the 
third, seven in the fourth; the spaces passed 
over in each second increasing as the odd 
numbers 1, 3, 5, 7,. 9, 11, etc. On account of 
the rapidity of the descent of heavy bodies, 
their velocity cannot be determined by direct 
experiment; nor could Atwood's machine be 
employed for the purpose with sufficient cer- 
tainty. The only mode by which an accurate 
result can be obtained is by measuring the 
length of a pendulum which makes a certain 
number of oscillations in a given time. Now 
the length of a pendulum vibrating seconds 
of mean solar time in New York, in vacuo, 
and reduced to the level of the sea, has been 
determined to be 39.10120 inches; and by a 
system of mathematical reasoning, which at 
present is unnecessary to be given, it is de- 
duced from the length of this pendulum that 
a body will fall about 16 feet during the first 
second of its descent; which is somewhat less 
than in London, and more than in Trinidad. 
From experiments made with the greatest 
care, it appears that the extreme amount of 
variation in the gravitating force between the 
equator and the poles is one part in 194 of the 
whole quantity; that is to say, any body 
which, at the equator, weighs 194 pounds, if 
transported to the poles would weigh 195 
pounds. The difference of gravitation, there- 
fore, at the equator and the poles is expressed 
by the fraction l-194th. 

The following table we have prepared to 
show the direct influence the varying force of 
gravity has on pendulums designed to vibrate 
seconds at the level of the sea, at various 
points along the Atlantic coast of America, 
and from the equator to 45° north, which is the 
highest latitude populous cities have yet been 
built on this continent. The measurement is 



174 



AMERICAN HOROLOGICAL JOURNAL. 



to the nearest hundredth of an inch, which is 
near enough for the clockmaker's purpose 
previous to his making the final adjustments. 
This table may be interesting and useful to 
our readers residing in any of the places 
mentioned, or in those of corresponding lati- 
tudes. In localities slightly above the level 
of the sea there will be no perceptible varia- 
tion from the table ; but in very high eleva- 
tions an allowance must be made for the 
variation of the force of gravity above the 
level of the sea. Capt. Kater's experiments, 
determining the length of a seconds pendulum 
in the latitude of London to be 39.13929, is 
the basis on which the table has been con- 
structed. 

Month of the Amazon river, Brazil 39 01 inches. 

Trinidad, West Indies 39.02 " 

Southern part of Cuba 39.01 " 

Havana, Cuba 39.05 " 

New Orleans 39 07 " 

Cape Hatteras 39,0S " 

New York City 3.1. 10 " 

Montreal 39. 12 " 

The difference in the length of a pendulum 
vibrating seconds at the level of the sea in 
any part of the United States, from the most 
southern part of Louisiana to the northern 
boundary of Minnesota, is not more than the 
.97 of an inch. Yet the result of even that 
slight difference will show a marked change 
on the rate of the pendulum, when we come 
to consider that part of the subject. 

Inclined Plane. — There are two properties 
connected with the motion of bodies on in- 
clined planes, which we must notice. The 
first is, that the velocity acquired by a body in 
descending from any elevation to a horizontal 
plane, is the same when it reaches the horizon- 
tal plane, whether falling freely in the vertical, 
or moving along an inclined plane at any angle 
of elevation. The second is, that the times of 
descent through all chords of the same circle to 
the lowest point, are equal, and equal to the 
time the body would take to fall through a 
height equal to the diameter of the circle. 

■ Thus : Let A B be the diameter 
of a circle, and C B, DB, and 
E B, chords of a circle. The 
time a heavy body would con- 
sume in falling vertically through 
the diameter is the same as that 
in which it would roll down the 
incline plane C B, D B. or E B — in other words, 



bodies placed at A, C, D, and E, and aban- 
doned at the same instant to the action of 
gravity, would arrive at B at the same time. 
In these proportions it is supposed, of course, 
that there is no resistance from friction. 

Cycloid. — -If a circle roll along a straight 
line, any point in the plane of the circle will 
generate a curve which is called a cycloid. 




Thus, if we take the straight line A B, and 
the circle C D, and roll the circle backwards 
and forwards along the straight line A B, a 
point in the edge of the circle C D will de- 
scribe the cycloidal curve E C F. To be 
more familiar, a wheel with a point projecting 
from the side of it at the extreme edge, if 
rolled along a work-bench, the projecting 
point will describe a cycloidal curve on the 
wall. This curve has many curious and val- 
uable properties. The line A B is called the 
base of the cycloid, and is equal to the cir- 
cumference of the generating circle C D, and 
the distance from C to E is the distance the 
point of suspension of a pendulum ought to 
be to fit into the cycloid. If a heavy body 
descend by the force of gravity in an inverted 
cycloid, the velocity which it acquires is 
exactly proportionable to the length of the 
cycloidal arcs PPD; so that, from whatever 




point, P P, it may begin to fall, it will arrive 
at the lowest point, D, in precisely the same 
time. If a body has to descend by the force 
of gravity from the point A to another point* 
D, not in the same vertical, it will accomplish 
the passage in less time by describing the 
cycloid A P P D than by moving in the 
straight line A D, or in any other path what- 
ever. 



AMERICAN HOROLOGICAL JOURNAL. 



175 



HEAT. 



NUMBER SIX. 

STEEL ITS MODES OF MANUFACTURE CAST STEEL 

INDIAN WOOTZ — ANNEALING METALS — ANNEAL- 
ING STEEL ENGRAVERS' PLATES, GOLD, SILVER, 

BRASS, ETC., WITHOUT CHANGE OF COLOR 

THEORY OF ANNEALING. 

We have now arrived at the point to con- 
sider the practical application and effects of 
heat in the multitudinous processes required 
in connection with the different branches of 
our various professions. 

The art of annealing, hardening, and tem- 
pering steel, constitutes, probably, one of the 
most delicate, curious, and useful branches 
connected with the mechanic arts. At first 
sight it appears sufficiently simple when, by 
heating a piece of steel to redness, and plung- 
ing it into cold water, it becomes hard ; on a 
closer inspection, however, the mind will 
soon discover that many operations and con- 
trivances require to be carried into effect by 
the operator in order to become efficient in 
the art, or be distinguished for skill and 
promptitude in execution. A slight knowl- 
edge of the processes will also discover that 
a certain amount of patient perseverance is 
required — an amount of which few who have 
been brought up at the desk, or behind the 
counter, can form the slightest idea. But we 
have not set out with the object to discourage 
the young practitioner, but rather to encour- 
age, and smooth for him the'path many have 
found so rough, but which we have always 
endeavored to explore without entertaining a 
sentiment of its hardship; and we would 
advise all young men who are just starting in 
life to go and do likewise. 

Steel is a compound of iron and carbon — 
sometimes formed from wrought iron by 
heating the w r rought iron in contact with car- 
bon, and sometimes formed from cast iron by 
depriving the cast iron of all impurities, ex- 
cept a small portion of carbon. The propor- 
tions of iron and carbon vary in the different 
qualities of steel; but in that ordinarily used 
the carbon rarely exceeds two per cent., and 
for some purposes it is as low as one per 
cent. Good ordinary tool steel contains about 
one and a-half per cent, of carbon. Previous 
to the introduction of Mr. Bessemer's method 



of producing steel direct from the cast iron 
without the intermediate operation of render- 
ing it malleable, the most common mode of 
manufacturing steel was by the process called 
cementation. The furnace in which iron is 
cemented and converted into steel has the 
form of a large oven, constructed so as to 
form in the interior of the oven two large and 
long cases, commonly called troughs or pots, 
and built of good fire-stone or fire-brick. 
Into each of these pots layers of the purest 
malleable iron bars and layers of powdered 
charcoal are packed horizontally, one upon 
the other, to a proper height and quantity, 
according to the size of the pots, leaving room 
every way in the pots for the expansion of the 
metal when it becomes heated. A hole is left 
in the end of one *of the pots, and three or 
four bars are left in such a manner that they 
can be drawn out at any period of the pro- 
cess and examined. After the packing of 
the pots is completed, the tops are covered 
with a bed of sand or clay in order to confine 
the carbon and exclude the atmospheric air. 
All the open spaces of the furnace are then 
closed, the fire is kindled, and the flame passes 
between, under, and around these pots on 
every side, and the whole is raised to a con- 
siderable intensity of heat, which is kept up 
for eight or ten days, according to the degree 
of hardness required. On the fifth or sixth 
day a test bar is drawn out of the converting 
pot for the purpose of judging whether the 
iron is at its proper heat, and to test the pro- 
gress of the carbonization. At this period of 
the process the film of iron is generally dis- 
tinguished in the centre of the bar, and the 
fire is generally kept up for a day or two 
longer in order that the iron may absorb 
more carbon. If, again, upon the trial of a 
bar, the cementation has extended to the 
centre, or, in other words, if the bars of iron 
have absorbed the carbonaceous principle to 
their innermost centre, the whole substance 
is converted into steel, and the work is com- 
plete. By this process carbon, probably in 
the state of vapor, penetrates and combines 
with the iron, which is thus converted into 
steel. 

Iron prepared by this process is called 
blistered steel; and when bars of blistered 
steel are heated, and drawn out into smaller 



176 



AMERICAN HOROLOGICAL JOURNAL. 



bars by means of the hammer, it acquires the 
name of tilted steel. Spring steel is the blis- 
ter steel simply heated and rolled; and Ger- 
man or shear steel is produced by cutting the 
bars of blistered steel into convenient 
lengths, and piling and welding them to- 
gether by means of a steam hammer. The bars, 
after being welded and drawn out, are again 
cut to convenient lengths, piled and welded, 
and again drawn out into bars. It is then called 
double shear steel, according to the extent 
of the process of conversion. Shear steel 
breaks with a finer fracture, is tougher, and 
capable of receiving a finer and firmer edge 
and a higher polish than blister or spring 
steel, and when well prepared is not much 
inferior to cast steel. Shear steel is very 
extensively used for those kinds of tools 
and pieces of work composed of steel and 
iron. 

Cast steel is made from fragments of the 
blister steel of the steel works. The process 
is nearly a hundred years old, but it still 
remains in principle unaltered. This method 
is to take the blister steel, converted into a 
certain degree of hardness, break it into 
pieces of convenient length, and place it in 
crucibles made of the most refractory fire 
clay, which are placed in furnaces similar to 
those used by brass founders. The furnaces 
are furnished with covers and chimney to 
increase the draught of air, and the crucibles 
are furnished with lids of clay to exclude the 
atmospheric air. The furnaces containing 
the crucibles are filled with coke, and for the 
perfect fusion of the steel, the most intense 
heat is kept up for two or three hours. When 
the steel is thoroughly melted it is poured 
into ingot moulds of the shape and size re- 
quired, and the ingots of steel, once only 
crude iron, but changed by chemical action 
into cast steel, are taken to the forge or roll- 
ing mill and prepared for the market into 
bars or plates, as may be required. Cast 
steel is the most uniform in quality, the hard- 
est and most reliable steel for cutting tools 
and all delicate mechanism. 

"What is termed Peruvian or Indian steel 
has for its base a material known in com- 
merce as uxtotz. It is manufactured, and is 
marketable throughout the East Indies as a 
metal suited to the production of cutting in- 



struments of a superior quality, but of which 
metal the method of manufacture remains 
but imperfectly known to European and 
American workmen. The Indian account of 
wootz-making is the following: "Pieces of 
forged iron are enclosed in a crucible with 
wood, and heated together in a furnace; the 
fire is urged by three or more bellows pecu- 
liar to the country, and thus the wood is 
charred, the iron fused, and at the same time 
converted into steel. The metal is suffered 
to crystallize in the crucible, and in this state 
it is exported." When wootz is submitted to 
a second and more perfect fusion, it improves 
so much as scarcely to be recognized; it is fit 
for the finest of purposes, and is said to be 
infinitely superior to the best English cast 
steel, but whether the superior properties 
arise from the mode of manufacture, or from 
the materials used, we are unable to say. 

Almost every one has heard of the famous 
Damascus steel; though in fact, little besides 
the name, and a vague notion that it is made 
in some parts of the Levant, appears to be 
known about it. Some authors assert that it 
comes from Golconda, in the East Indies, 
where, they add, a method of tempering 
with alum, which the Europeans have hither- 
to been unable to imitate, was invented. It 
is moreover asserted that the 1 eal Damascus 
blades emit a fragrant odor on being bent, 
and while they bent like a switch, were of so 
stern a temper that they would cut through 
iron without injury to the edge. The com- 
position of the material formerly so cele- 
brated as the steel of Damascus has given 
rise to many investigations with a view to 
imitate it, but as yet with only partial suc- 
cess. Silver, platinum, rhodium, gold, nickel, 
copper, and even tin, have an affinity for 
steel sufficiently strong to make them com- 
bine chemically with it, and they have all 
been used as an alloy for various special pur- 
poses, which our limits prevent us for the 
present from describing. 

Annealing is a process used in the manufac- 
ture of metals, and also in glass-making. In 
glass-making it consists in placing the ar- 
ticles, whilst hot, in a kind of oven or furnace, 
where they are suffered to cool gradually. 
They would otherwise be too brittle for use. 
The difference between annealed and unan- 



AMERICAN HOROLOGICAL JOURNAL. 



177 



nealed glass, with respect to brittleness, is 
very remarkable. 

When an unannealed glass vessel is 
broken, it often flies into small pieces, -with 
a violence seemingly very unproportioned to 
the stroke it has received. In general it is 
in greater danger of breaking from a vex*y 
slight stroke than from one of very consider- 
able force. A vessel will often resist the 
effects of a pistol bullet dropt into it from 
the height of three or four feet, yet a grain 
of sand falling into it will make it burst into 
small fragments. This takes place sometimes 
immediately on dropping the sand into it; 
but often the vessel will stand for several 
minutes after, seemingly secure, and then, 
without any new injury, it will fly into pieces. 
If the vessel be very thin, it does not break 
in this manner, but seems to possess all the 
properties of annealed glass. Glass is one 
of those bodies which increase in bulk when 
passing from a fluid to a solid state. When 
it is allowed to cxwstallize regularly, the par- 
ticles are so arranged that it has a fibrous 
texture. It is elastic, and susceptible of long 
continued vibrations; but when a mass of 
melted glass is suddenly exposed to the cold, 
the surface crystallizes and forms a solid 
shell round the interior fluid parts. This 
prevents them from expanding when they be- 
come solid, and therefore they have not the 
opportunity of a regular crystallization, but 
are compressed together with little mutual 
cohesion; on the contrary they press outward 
to occupy more space, but are prevented by 
the external crust. By the process of anneal- 
ing, glass is kept for some time in a state ap- 
proaching to fluidity; the heat increases the 
bulk of the crystallized part, and renders it 
so soft that the internal parts have the oppor- 
tunity of expanding and forming a regular 
crystallization. 

In the manufactures in which the malleable 
metals are employed, annealing is used to 
soften a metal after it has been rendered hard 
by the hammer, and also to soften cast iron, 
which is rendered very hard and brittle by 
rapid cooling. In the manufacture of steel 
articles which are formed by the hammer, and 
require to be filed or otherwise treated, and 
in which softness and flexibility are essential 
to the change, annealing is absolutely neces- 



sary. Annealing is not less necessary in the 
drawing of wire, whether iron, copper, brass, 
silver, or gold. The operation of draw ng 
soon gives the wire a degree of hardness and 
elasticity which, if not removed from time to 
time by annealing, would prevent the exten- 
sion of the wire, and render it extremely 
brittle; and the same operation is also neces- 
sary in rolling or flattening those metals 
which are in a cold state, such as brass, silver, 
gold, etc. The methods often employed for 
annealiug iron and steel are very injurious, 
and materially injure the latter when it is to 
be used for any important or delicate pur- 
pose. After the articles have been formed 
into shape they are sometimes placed on an 
open fire, slowly raised to a red heat, and 
then allowed as gradually to cool. By this 
method the surface of the steel will be found 
considerably scaled, from the action of the 
oxygen of the atmosphere. When it is re- 
membered that steel consists of iron joined 
to carbon, it will be evident that the steel 
immediately under the scaly oxide will be de- 
prived of its carbon, which has been carried 
off by the attraction of the oxygen, and in 
consequence will lose the property of ac- 
quiring that degree of hardness necessary. 
Nothing, therefore, can be more obvious than 
that steel should be annealed in close vessels, 
to prevent that effect. For this purpose the 
pieces should be in a trough or recess made 
of soap-stone or fire-brick, and stratified with 
ashes or clean sand, and finally covered with 
a thick covering of the same; but if the size 
of the vessel be small it may be covered with 
its own materials. 

This oven or trough must now be heated 
by the flame of a furnace passing under and 
around it, till the whole is of a red heat, and 
then it must be suffered to cool without letting 
in the air. The articles so treated will be 
much softer than by the other method, and 
the surface, instead of becoming scaled, will 
have acquired a metallic whiteness from the 
presence of a quantity of carbonaceous mat- 
ter contained in the ashes in which they were 
imbedded. They will become so flexible, also, 
as to allow them to bend considerably with- 
out breaking, which is very far from being 
the case before the operation. 

Wire, especially that of iron and steel, 



178 



AMERICAN HOROLOGICAL JOURNAL. 



should be treated in a similar way when it is 
annealed. The wire used for some purposes 
requires to be soft, and is sold in that state. 
If the wire, after finishing, when it is bright 
and clean, were to be annealed in contact 
with oxygen, it would not only lose all its 
lustre and smoothness, but much of its ten- 
acity. The process above mentioned will 
therefore be particularly necessary in anneal- 
ing finished wire, as well as softening it from 
time to time during the drawing. Copper 
and brass suffer much less than ii-on and 
steel from annealing in an open fire, and they 
do not require to be heated above a low red 
heat ; if, however, the lustre is to be preserved 
a dote vessel is desirable. 

In casting minute pieces of pig iron, which 
is generally done in damp sand, the metal 
possesses the property of steel to such a degree 
as to assume, by its rapid cooling, a degree 
of hardness equal to hardened steel ; at the 
same time the articles are so brittle as to 
break on falling on the ground. When, how- 
ever, these goods are treated in the way 
above directed, they acquire a degree of soft- 
ness which renders them penetrable to the 
file, and at the same time capable of bending. 
In this state they are much less tenacious 
than steel, but still so much so as sometimes 
to be sold in the form of cutlery and other 
household utensils. 

Less than a certain amount of heat will fail 
to make steel hard, but on the contrary will 
soften it; and sometimes this effect is useful. 
For instance, suppose a piece of steel is too 
hard to be dressed by the file, or cut with the 
turning tool, and time will not permit of its 
being softened in a box with charcoal powder ; 
the steel may be heated to a cherry red heat 
in an open fire, then drawn out of the fire 
and allowed to cool down till the red heat is 
not visible by daylight, but can be seen in a 
dark place behind the f^rge ; then to be 
plunged at this heat into cold water, and 
allowed to remain in the water until quite 
cool. When taken out it will be found to be 
much softer, and will yield to the file or the 
turning tool readily. Instead of pure water, 
some use a mixture of soap and water with 
good results. 

The change which metals undergo by an- 
nealing is not yet thoroughly understood. 



Most of the malleable metals are susceptible 
of two distinct forms; one called the crystal- 
line form, which they assume by slow cool- 
ing, and the other the fibrous, which is 
acquired by hammering or rolling. When 
this, however, is carried beyond a certain 
point, the metal becomes so hard that it is 
not capable of being bent without breaking. 
AD the malleable metals in the ingot, or in 
their cast state, are brittle and exhibit a 
crystalline fracture. By hammering or roll- 
ing they become more tenacious, break with 
difficulty, and exhibit what is called a fibrous 
fracture. At the same time they become 
stiffer and more elastic, but they lose the 
latter properties by annealing, but become 
more malleable. 

If the annealing, however, be long con- 
tinued the malleability diminishes, and they 
have again a crystalline fracture. Zinc, 
when drawn into wire, becomes very flexible, 
and possesses a degree of tenacity not infe- 
rior to that of copper; but if it be kept in 
boiling water for a length of time it will as- 
sume its original brittleness, and show a 
crystalline appearance when broken. This 
proves that the particles of metal can change 
their arrangement without losing their solid 
form; which is still further confirmed by the 
fact that brass wire loses its tenacity by ex- 
posure to the fumes of acids, and even by the 
presence of a damp atmosphere. Those parts 
of the brass work in a turret clock that have 
been much exposed to an impure atmos- 
phere will be found in the same condition, and 
the manufacturers of common pins are 
obliged to keep their wire in a dry atmos- 
phere, or immersed in water. If the wire be 
first moistened and then exposed to the air, 
it will assume the brittle state much sooner. 
This is not caused by the moisture, but by the 
action of the air on the moistened surfaces. 

The process of softening or decarbonizing 
steel suitable for the steel engraver, has al- 
ways been one of difficulty; and we will 
conclude the subject of annealing by giving 
the methods practised by two celebrated 
British and American steel engravers. Mr. 
Jacob Perkins, an ingenious New England 
artist, conducted the decarbonizing process 
by enclosing the plate of cast steel, properly 
shaped, in a cast-iron box, filled about the 



AMERICAN HOROLOGICAL JOURNAL. 



170 



plate to the thickness of about half an inch, 
with oxide of iron, or rusty iron filings, and 
in this state the box was luted close, and 
placed in a regular fire, where it was kept at 
a red heat during from three to twelve days. 
Generally about nine days he found suffi- 
cient to decarbonize a plate five-eighths of an 
inch in thickness. 

Mr. Charles Warren, a celebrated English 
engraver, also enclosed his plates in a cast- 
iron box, but covered them up with a mixture 
of iron turnings and pounded oyster shells, 
and placed the box for only a few hours in a 
furnace as hot as it could be and not melt the 
cast iron. But a Mr. Hughes, a pupil of Mr. 
Warren's, found that the steel was not always 
sufficiently and uniformly soft (particularly 
for the purpose of engraving in mezzotinto), 
and imagined that those occasional defects 
were owing to a deficiency of heat in the 
cementing process; accordingly, he substi- 
tuted a case of refractory clay for the cast-iron 
one, and, applying a considerable higher heat 
than the cast-iron box would have endured 
without melting, was enabled to obtain plates 
so soft that they might be bent over the knee. 



MEASURING HAIB-SPltlMS. 



Editoe Hoeologicax, Jouenal : 

I am inclined to find a little fault with Mr. 
Rawson's idea for the measurement of the 
strength of hair-springs. His use of the mi- 
crometer for the purpose, I think, must give 
results quite unreliable. In the first place, 
no spring wire is homogeneous in its compo- 
sition, and consequently cannot be uniform 
in its temper. In the article on Heat, in the 
same number, the practical impossibility of 
getting a bar of metal entirely uniform in its 
molecular constitution, is given as the reason 
for the want of exact uniformity in the 
result of the experiments there described. 
The same unreliability must exist in spring 
wire, and I cannot possibly conceive how 
linear measurement can give any indication 
of such a fault. 

Secondly, the linear measurement of a 
spring will be the same precisely, whether the 
spring be soft-tempered or hard; but the 
action as a spring depends eminently on these 



i qualities. Thirdly, the effective force of a 
i spiral is so modified by the closeness of the 
j coils, as well as by the total length of the 
spring, that any external measurement will 
fail to give a very sure guide to its elastic 
force. It is on this elastic force that watch, 
springers depend for determining the proper 
point at which the hair spring should be 
pinned in the stud, to give the balance the 
requisite number of vibrations per minute;- 
fcr, by lengthening or shortening the spring, : 
as held by the tweezers, and counting the 
vibrations of the balances, this point can be 
determined with great exactness. 

This system of adjustment depends for its 
success wholly on the elasticity of the spring 
— not on its width or thickness; of course 
these elements enter into and help to make 
up that force, but the temper, which is also an 
important ingredient, will most certainly elude 
the measurement of even a microscopic mi- 
crometer. For these reasons I think any in- 
strument for determining this force should be 
based in its principles upon the absolute 
test of that quality in each individual spring. 

For some time I have had in use one of 
Bissell's Staking tools, and cannot refrain 
from speaking of it with pleasure. It is very 
well made, and admirably adapted to the 
purpose. I think it can be used very conve- 
niently as a tool for stretching the teeth of 
wheels. The wheel, of course, cannot be cen- 
tred by the pivots, but can be either from the 
arbor or from the circle of the pinion leaves* 
which will answer every purpose, as the 
teeth are afterward rounded up in the round- 
up tool with the pivots as centres. I think 
Mr. Bissell, will make it more useful, if he can 
afford to add to the number of punches, two 
or three, for the purpose I have named ; or, 
if that is too much, let him leave out the drill 
stock, and give these punches in its place. I 
think most workmen would prefer that 
change. Altering the dep thing in the very 
common jewelled Swiss watches must very 
often be done or the watch will not even go. 
And there is no ready way to do except to 
enlarge or diminish the size of the wheels 
which can speedily be done (and neatly) with 
a stretching punch and a rounding-up took 

R. Cowles. 
Cleveland. 



180 



AMERICAN HOROLOGICAL JOURNAL. 



ABSTRACT OF RATES OF CHRONOMETERS ON TRIAL 



Nauh or Maker. 



M. F. Dent 

Chittenden 

Reid and Sons 

Lowry 

Kingston 

C. Frodsham 

E. Dent & Co 

Glover 

McGregor & Co . . . 

F. Fletcher 

J. B. Fletcher 

Shepherd & Son. . . 
Parkinson & Bouts 
Gowland ... 

C . Frodsham 

Lister & Sons .... 
McGregor & Co . . . 

Davison 

Penlington 

J . Fletcher 

Roskell &Co 

Dobbie 

Hennessy 

Reid & Sons 

Weiehert 

Shepherd & Son. . . 

Webb 

Lister & Sons 

Eiffe 

Eiffe, Jun 

D. Reid 

Webb 

Whiffin 

Eiffe 

Gowland 

Thicthener 



No. 



25334 

779 

1491 

1656 

5321 

3345 
3092 
354 
4173 
2921 

2969 
1737 
1147 
2711 
3364 

635 

4172 
1671 
1799 
2679 

j.7 aa. 

b >» 7 :ti 

4323 
1613 
1492 
2215 

1723 

5550 

636 

5(52 

100 

1870 

5552 

350 

299 

1279 



.Address of Makes. 



33 Cockspnr street, London. 
10 Wilton rd. , Hackney, Lond. 
41 Grey street, Newcastle. 
66 High street, Belfast. 
13 High street, Ranisgate. 

84 Strand, London. 
61 Strand, London. 

4 Swinton street London. 
38 Clyde Place, Glasgow. 

148 Leadenhall street, London 

148 Leadenhall street, London. 
53 Leadenhall street, London . 
59 Gracechurch street, London . 
178 High street, W. Sunderland 
84 Strand, London . 

12 Mosley street, Newcastle. 
38 Clyde Place, Glasgow. 
6 Side. Newcastle. 

3 St. George's Crescent, Li verp. 
148 Leadenhall street, London. 

21 Church street, Liverpool . 
24 Clyde Place, Glasgow. 

5 Wind street. Swansea. 
41 Grey street. Newcastle. 
112 Rothsay Terrace, Cardiff. 

53 Leadenhall street, London. 

4 Pnlleu's Row, Islington. 
12 Mosley street. Newcastle. 
Arnershain, Buckinghamshire . 
Amersham, Buckinghamshire . 

41 Grey street, Newcastle. 
4 Pulleu's Row, Islington. 
41 Bamsbury road, London . 
Amersham. Buckinghamshire. 
178 High street, W. Sunderland 



Construction or Balancb. 



1000 324 Goswell road, London. 



(No information received.) 
Auxiliary as in former years . 
Auxiliary acting in cold . 
Auxiliary compensation . 
Auxiliary acting in cold. 

(No information received . ) 
Dent's patent balance. 
Auxiliary compensation. 
Poole's auxiliary . 
Auxiliary compensation . 

Auxiliary compensation. 

Auxiliary compensation . 

Auxiliary to balance, acting in extremes . 

Auxiliary compensation . 

(No information received.) 

Poole's auxiliary. 
Auxiliary compensation . 
Auxiliary compensation . 
Auxiliary compensation balance. 
Auxiliary compensation . 

Kullberg's double rim balance, without auxiliary 
Ordinary compound balance, Poole's auxiliary. 
Auxiliary compensation . 
Auxiliary acting in all temperatures. 
Ordinary balance, with original auxiliary . 

Auxiliary compensation. 

Auxiliary acting in all temperatures . 

Poole's auxiliary. 

Improved application to the pendulum spring. 

Patent balance: unassisted figure. 

Auxiliary balance. 

Auxiliary acting in all temperatures. 

Auxiliary compensation. 

Improved application to the pendulum spring. 

Ordinary balance with auxiliary. 

Double locking detent and bi-conical timing 
spring; plain balance. 



Thp sign 4- indicates that the rate is gaining. 

f During these weeks the Chronometers wer:> placed in the chamber of a stove heated by jots of gas. The gas flames are exterior 

to the chamber, into which none of the iaj irious products of combustion can entor. 
F.ilTe 2^9 is ap cket Chronometer; EilTe 562 is an eight- lays; all the rest are two-days performers. 
The ratings commenced January 15th, and ended August 6th, bj that the duration of the trials was 29 weeks. 



"We present above a table called an 
" Abstract of the principal changes of rates of 
Chronometers on trial for purchase by the 
Board of Admiralty, at the Royal Observa- 
tory, Greenwich, 1870." In addition, we have 
thought it would interest onr readers to give 
some explanation of the nature of these trials, 
the causes of the failures that disappoint so 
many of the competitors, and a general review 
of the trials of the last thirty years. 

Th« test prescribed for these chronometers 
is about as severe as well can be, and not 



transcend the limits of reasonable require- 
ment. The Board of Admiralty does not 
require that chronometers purchased by them 
shall be limited to any particular size, style, 
or manner of construction, nor that they shall 
possess any special property in their adjust- 
ments. Uniformity of performance, being the 
desired result of the various adjustments 
bestowed on chronometers for the purpose of 
producing time-keeping qualities, is alone the 
qualification sought for, and the test admin- 
istered in the Greenwich Observatory is well 



AMEKICAN HOROLOGICAL JOURNAL. 



181 



AT TEE ROYAL OBSERVATORY, GREENWICH, 1870. 



Least 

Weekly 

Sum. 


In what Temperature. 


Greatest 
Weekly- 
Sum. 


In what Temperature. 


Difference 

between 

the Greatest 

and Least. 


Greatest 

Difference 

between one 

Week and 

the next. 


Extremes of 
Temperature. 


I 


Degrees Fahrenheit. 


f 


Degrees Fahrenheit. 


* 


* 




- 5.3 


71 to 92f 


+ 0.2 


41 to 51 


5.5 


3.8 


35-66 


- 1.7 


do. 


+ 7.0 


33 to 38 


8.7 


5 3 


do. 


- 13.0 


67 to 77 


+ 0.5 


72 to 90f 


12.5 


5.1 


63-87 


- 9.5 


62 to 69 


+ 3.5 


51 to 58 


13.0 


6.0 


62-72 


- 6.1 


40 to 51 


+ 7.1 


68 to 72 


13.2 


6.5 


43-73 


+ 4.5 


do. 


+ 20.3 


67 to 77 


15.8 


5.7 


63-87 


4- 6.1 


63 to 84f 


+ 21.8 


35 to 48 


15.1 


6.3 


55-84 


- 17.6 


38 to 43 


- 1.1 


56 to 69 


16.5 


5.8 


48—35 


- 13.5 


85 to 95f 


0.0 


41 to 51 


13.5 


7.5 


43-73 


- 1.3 


63 to 84f 


+ 12.9 


67 to 77 


14.2 


7.2 


95-62 


- 2.0 


33 to 38 


+ 15.8 


51 to 58 


17.8 


5 8 


48-33 


- 13.5 


55 to 73f 


■H 2.4 


69 to 87f 


15.9 


6.9 


63-50 


- 9.0 


71 to 92f 


+ 4.0 


41 to 51 


13.0 


9.2 


55-84 


- 5.8 


63 to 8lj 


+ 7.0 


51 to 58 


12.8 


9.4 


35-66 


- 6.5 


33 to 38 


+ 10.7 


72 to 90f 


17.2 


7.5 


76-96 


- 21.3 


52 to 63 


- 7.7 


68 to 72 


13.6 


9.3 


92-52 


- 16.5 


56 to 71 


- 5 


72 to 90 


16.0 


8.8 


63-90 


- 1.0 


33 to 38 


-t-21.2 


67 to 77 


22.2 


6.6 


95-62 


- 17.5 


4U to 51 


- 0.6 


50 to 57 


16.9 


9.9 


38-48 


- 6.7 


do. 


+ 9.0 


43 to 49 


15.7 


11.1 


51-38 


- 9.3 


68 to 72 


4- 9.3 


71 to 92f 


18.6 


10.4 


95-62 


- 10.3 


81 to 96f 


+ 9.0 


33 to 38 


19.3 


11.1 


35-66 


- 6.0 


33 to 38 


+ 12.5 


67 to 77 


18.5 


11.6 


63-87 


- 2.7 


40 to 51 


+ 18.7 


85 to 95f 


2.1.4 


11.7 


95-62 


- 4 5 


33 to 38 


+ 28.5 


68 to 72 


33.0 


. 7.0 


43-73 


- 0.4 


do. 


+ 21.0 


62 to 69 


21.4 


13.2 


do. 


- 28.9 


68 to 75 


- 5.8 


35 to 48 


23.1 


13.5 


92-52 


- 23.0 


43 to 51 


- 0.2 


68 to 77 


22.8 


16.5 


43-73 


- 28.0 


71 to 92f 


- 6.1 


55 to 73f 


21.9 


17.0 


71-92 


- 42.5 


33 to 38 


- 14.8 


62 to 69 


27.7 


14.2 


95-62 


- 12.7 


43 to 51 


+ 26.6 


68 to 72 


39.3 


10.4 


do. 


- 26.4 


56 to 69 


+ 2.4 


38 to 43 


28.8 


17.4 


50-58 


- 15.3 


43 to 51 


+ 33.6 


68 to 72 


48 9 


12.1 


43-73 


- 24.0 


33 to 38 


+ 23.5 


69 to 87 1 


56 5 


33.0 


68-77 


- 14.3 


41 to 66 


+ 44.0 


85 to 95f 


58.3 


38.3 


35-66 


+ 6.6 


72 to 90f 


+ 72.2 


68 to 72 


65.6 


37.3 


48-33 



The Chronometers are placed in order of m9rit, their respective positions being determined solely by consideration of the irregu- 
larities of rate exhibited in the Table above. 

The Chronometer Eiffe 299 (pocket) accidentally ran down on February 6 ; the rate for the week February 5 to 12 is therefore 
wanting, and, consequently, the position of the Chronometer in the Tables is not necessarily correct. 



calculated to develop any defect in this par- 
ticular. 

Chronometer makers or dealers are per- 
mitted to deposit in the Greenwich Observ- 
atory, in charge of the Astronomer Royal, 
who is the sole arbiter in the decisions made, 
each a limited number of marine time-keep- 
ers on trial for purchase by the Board of Ad- 
miralty. The trial usually begins early in Jan- 
uary, and continues about twenty-nine weeks. 
During the cold weather they are exposed to 
the greatest degree of natural cold possible 



in that climate ; at other times to medium 
temperatures, while a portion of the period 
they are placed in an oven in which the heat is 
created artificially, but rarely exceeding 100° 
Fahr. It is designed to test them in all the 
degrees of temperature within the range men- 
tioned. At the end of each week the gain or 
loss is noted, together with the maximum and 
minimum readings of the thermometer. These 
weekly limits of temperature do not, however, 
necessarily indicate the average, to ascertain 
which, recourse is had to a chronometrical 



182 



AMERICAN HOROLOGICAL JOURNAL. 



thermometer, having the balance so con- 
structed that its rate undergoes great changes 
by small variations of temperature, and its 
gain or loss during any period, therefore, 
showing the average temperature, but ex- 
pressed in seconds of time instead of degrees 
of the thermometer. 

A table is first prepared, showing the run- 
ning of the chronometers for each successive 
week ; that is, in the order of time. During 
the early part of the trial the temperature is 
purposely raised from one extreme to the 
other ; then the trial continues through all 
the medium temperatures, and in the latter 
part of the term the temperature is consider- 
ably raised ; while in the last month it is al- 
lowed to fall again as low as the natural con- 
dition of the atmosphere at that season will 
admit. A second table is prepared in which 
the rates of the chronometers for each week 
is shown in the order of temperature, which 
shows more readily what the general and par- 
ticular effect has been in each case, by the 
gradual increase of temperature. A third 
table is then prepared, being an abstract of 
the first two, and the one we publish, show- 
ing for each chronometer in what week it 
made its " least weekly sum," and in an ad- 
joining column, in what week its " greatest 
weekly sum " occurred. Another column 
shows the " difference between the greatest 
and least," and in the next column is shown 
the "greatest difference between one week 
and the next." The rule for classifying the 
chronometers is as follows : 

Multiply the amount in the column headed 
" greatest difference between one week and 
the next " by 2, and add the amount in the 
column headed " difference between the great- 
est and the least," and the trial number is ob- 
tained. Obviously, the less the trial number, 
the higher the chronometer stands in the or- 
der of excellence ; and it is in this manner 
solely, that the standing is determined. When 
the trial is terminated, the Board of Admi- 
ralty selects for purchase a certain number of 
those that stand highest on the list, accord- 
ing to the needs of the service, and instructs 
the Astronomer Royal to offer the respective 
owners certain prices for them, considerably 
higher than could be obtained in the ordinary 
course of trade ; so that the price paid is in 



the nature of a prize. Of course, what is most, 
prized, is the honor of heading the list, and 
the approval of the Admiralty. 

In the manufacture of chronometers, after 
the highest degree of excellence is secured in 
the purely mechanical construction, and, as 
far as the eye can perceive, each part is well 
adapted to the exercise of its function, and 
bears a proper relation to every other part, 
three difficulties arise to defeat the prime ob- 
ject for which they are designed, viz., unifor- 
mity of performance. These defects are, accel- 
eration of the rate, imperfect compensation, and a 
want of isochronism. 

Acceleration of rate is due to an inherent 
property in a new balance spring, generally 
believed to be found in greater degree in 
springs of high temper. There is considera- 
ble difference of opinion among horologists 
as to the reason for this defect, which shows 
itself in a steadily increasing rate, lasting 
from a few weeks to several years. Eventu- 
ally the difficulty ceases to exist, and it is 
claimed that those chronometers which pos- 
sess this property when new, generally be- 
come the most steady when the acceleration 
ceases ; but, at all events, they appear none 
the worse for having passed through the 
ripening process. Acceleration cannot be 
remedied by putting in soft balance springs, 
as that produces a worse defect, found in 
irregular performance. The writer is certain 
that the spring should be highly tempered, 
and that this should not necessarily cause any 
material acceleration of the rate, nor, if it 
does, should it continue through any consid- 
erable length of time. 

Oar readers will have noticed nearly all the 
chronometers entered at Greenwich for trial 
in the year 1870, were described as having 
some sort of auxiliary compensation; and the 
same remark applies to every year since 1850, 
at which time the Board of Admiralty began 
to publish with the annual report a descrip- 
tion of any peculiarity of escapement or bal- 
ance. It is a well ascertained fact that most 
chronometers with the ordinary construction 
of balance, when adjusted to maintain the 
same rate in extreme temperatures, say 30° 
and 100°, go considerably faster in the mean 
temperature, or 70°, or what is the same 
thing, whatever the rate of such a chronome- 



AMERICAN HOROLOGICAL JOURNAL. 



183 



ter in 70°, it goes slower in either extreme ; 
and this quantity varies from a small fraction 
of a second to six seconds, in some cases, per 
day. It rarely happens that chronometers 
with ordinary balances have the contrary 
property of losing in the mean temperature, 
and when they do, in very slight degree. With- 
out attempting to go into the reasons for this 
interesting fact, it is enough for our present 
purpose to point out that, during the last 
twenty years, certainly, the English makers 
have been impressed with the importance of 
overcoming this difficulty in the compensa- 
tion. Several years since, Mr. Charles Frod- 
sham publicly said in effect that the man who 
could invent a balance having all the good 
qualities of that ordinarily used, and none of 
the unstable properties of the auxiliary com- 
pensation or others of similar design, and 
which should remedy this one defect, " ought 
to have a golden feather put in his cap." 
Although there have been nearly as many 
inventions to remedy this defect in the com- 
pensation as there have been competitors for 
the highest honors at Greenwich, yet the 
problem does not appear positively to have 
been solved. 

The effect of a proper isochronal adjust- 
ment is shown in the maintenance of a uni- 
form rate under varying motive power. If, 
therefore, this adjustment is not perfect, 
inasmuch as chronometers usually in such 
cases go faster with a decrease of power, there 
is a tendency to gain, as the oil thickens. 
This defect is not developed to any great 
extent in a short trial of twenty-nine weeks. 
Yet it probably, in some cases, contributes to 
failure, as some kinds of oil may slightly 
change in fluidity with variations of temper- 
ature, thus causing fluctuations in the extent 
of the arcs of vibration. 

The late Mr. John Poole, of London, was 
probably the best of the English makers. The 
workmanship on his chronometers was of the 
highest order, in addition to which his spring- 
ing was of superior merit ; but undoubtedly 
much of his success was due to what he 
called his auxiliary, though as it was merely 
a check acting in cold, we never could see 
just why this name was given to it. His 
work was very popular with the trade, and 
many dealers purchased his chronometers, 



having their names put on the dials, and 
entered them at these trials, but whatever 
credit they gained was due to Mr. Poole, 
rather than those whose names they bore. It 
is only fair to the other competitors to Bay 
that his make stood the best chance of being 
first on the list, as there were sometimes as 
many as twelve'entered in one year by parties 
who had purchased them from him. Poole's 
auxiliary was constructed by securing on the 
outside of the rim of the balance, at the point 
opposite the end of the arm, a small cock, 
made concentric with the centre of the bal- 
ance, and parallel to the circular rim. 
Through the end most distant from the arm 
a set screw passed which nearly touched the 
rim in medium temperatures. The chronom- 
eter was then adjusted to go the same in 
high and medium temperatures, which threw 
all the error of compensation on the side of 
the adjustment for cold, that is, it lost exceed- 
ingly in cold. By the aid of the set-screw, 
this was remedied, until it corresponded with 
the adjustment for other temperatures. Prob- 
ably most of the auxiliaries are on this 
principle: Dent's, Hartnup's, and Kullberg's 
balances are on the principle of flat rims, in- 
stead of upright, and the arms as well as the 
rims are laminated. Excepting Poole'sj 
these balances, or any others with auxiliaries, 
are seldom seen in the chronometers manu- 
factured for ordinary trade, and the use of 
them is mainly confined to those instruments 
made expressly for the Admiralty trials. 

Some of the auxiliaries are constructed to 
act only in heat. "We notice, in 1867, that 
Webb entered one such, and in all the tem- 
peratures up to 81° it was of unusual excel- 
lence ; but at that point the auxiliary began 
to act, and so overdid the matter in the 
temperatures between 81° and 95° that it 
caused it to rank the fifty-first in the list. It 
is a curious circumstance that the renowned 
maker, Jurgensen, never succeeded in rising 
higher than thirty-first in the list, which per- 
haps was due to the fact that he clung tena- 
ciously to a gold balance spring, of the merits 
of which he wrote considerably. 

We close this article by adding a table, 
compiled from the annual reports of trials of 
chronometers at Greenwich since 1840, show- 
ing the names of the successful competitors 



184 



AMERICAN HOROLOGICAL JOURNAL. 



and the years in which they respectively 
stood first in the list. The names are 
arranged in the order of merit, according to 
the trial number given by the formula men- 
tioned. An inspection will show that the 
highest honors have not been monopolized 
by any particular maker, although Poole 
heads the list five times, Molyneux three 
times, and Kullberg, Loseby, Lawson, P. 
Birchall, and Fletcher twice each. It is 
worthy of note that since 1850 two only 
of the chronometers had balances of " ordi- 
nary construction," and they had the peculiar- 
ity of a "slight alteration." 



Year. 
1870.... 
1863 
1867 


Maker. 

....M. F. Dent 

....J. B Flelcher 

....Sewill 


Trial Num 

13.1 

. 14.0 

162 


1868 
1847 
1869.... 
1852.... 


...P. Birchall 

...J. B. Fletcher 

Poole 


16.5 

17.3 

17.6 


1854.... 


....Poole 


17.6 


1848 
1864.... 


.... Loselvy 


17.9 

18.6 






18.7 


1859 
1866.... 




. 19.0 
19.0 


1842.... 




. 19.2 


1840 




20.0 


1845 
1843.... 


...Poole 


21.0 

21 3 


1850 
•1862.... 




22 1 

22.3 


1844-.. . 
18tl 




23 7 


|1861 




24 5 


1860. . .. 


. . . . P. Birchall 


. 25.3 


1858 
1846 




26.7 

26.9 


1853 
1855 
1849 . . . . 


Eiffe 


30.2 

30.2 

33.8 


fl856 
1857 
1851.... 




36.7 

39.6 









METALS AND ALLOYS. 

Chemistry has made us acquainted with 
about forty-three different metals, of which 
not more than twelve are of general use in 
the industrial arts. These are iron, copper, 
lead, tin, zinc, mercury, gold, silver, platinum, 
arsenic, antimony, and bismuth. In this 
limited list platinum is always employed in a 
pure state, although an alloy of platinum and 
lead, in definite proportions, is now known to 
exist, and is being experimented upon. Iron, 
copper, lead, tin, zinc, gold, and silver are all 
very extensively employed in their pure state; 
but when hardness is required an alloy is 



• Made b>- Kullberg. 



f Made by Poole. 



used, which is a mixture of two or more 
metals. This is not a strict definition of alloy, 
for mercury unites readily with most metals, 
and all the compounds so formed are called 
amalgams. "What necessity there is for this 
distinction we cannot see, but universal cus- 
tom has given to all the alloys of mercury the 
name of amalgams. 

Although the number of useful metals is 
so limited, the number of alloys may be in- 
definitely extended; probably two or three 
hundred alloys are known, but not more than 
about sixty have been studied with care. An 
alloy may be regarded as a new metal, since 
its properties may be quite different from, 
and perhaps generally do not much resemble 
either of its component metals. Metallic 
compounds, like the chemical, often produce 
unexpected results ; and if the metallic mix- 
ture was only a mechanical one, the resultant 
would be anticipated to be a mean of the 
metals so mixed; but as the alloys have totally 
different 'properties from their originals, we 
must conclude that, at least in many instances, 
the combination is chemical, not mechanicaL 

The power of forming alloys is highly valu- 
able to the manufacturer, as it enables him to 
create a new metal adapted to such wants as 
the continually advancing state of his art 
requires. As illustration of the idea, take 
type-metal. Printers required types ; the 
harder metals, iron and copper, were too 
hard — cutting the paper ; the softer, tin and 
lead, were too soft — battering down by the 
necessary pressure ; but a combination of two 
or three metals was the very thing. An alloy 
of one part antimony with three or four of 
lead, gave the proper mean, partaking of 
the character of both originals, and varying 
as the quantities were varied. 

As an example of chemical combination 
we may take an alloy of tin and copper — 
both soft, flexible, and ductile; but nine 
parts copper and one of tin makes a tough, 
rigid metal, used in casting ordnance, and 
called gun -metal. It admits of neither roll- 
ing nor drawing, and, by increasing the pro- 
portion of the softer metal, tin, the hardness 
of the alloy is increased. One-sixth of tin 
produces the maximum degree of hardness ; 
one-fourth of tin produces the highly sono- 
rous bell-metal ; two parts of copper and one 



AMEKICAN HOEOLOGICAL JOUKNAL. 



185 



of tin produces an alloy so hard that it can- 
not be cut with steel tools, and when struck 
with a hammer, or even suddenly heated, it 
flies in pieces like glass, and presents a highly 
crystalline structure. It retains no trace of 
the red color of copper, being quite white, 
and is susceptible of such an exquisite polish, 
not very easily tarnished, that it is used for 
mirrors, and is called speculum metal. 

Alloys may be varied by the introduction 
of several metals. Brass, for example, is an 
alloy of copper and zinc ; but the best brass 
for turning at the lathe is made by the addi- 
tion of a small quantity of lead, which, how- 
ever, renders it unfit for hammering. In 
forming alloys on a large scale, the metals, 
while fluid, strongly tend to separate accord- 
ing to their specific gravity, the heavier going 
to the bottom ; and where this difference is 
considerable, they require constant stirring 
till cold, and then breaking up and re-melt- 
ing ; even then it is sometimes difficult to 
form a bar entirely homogeneous throughout. 
In most alloys of three or more metals it is 
best to combine them first in pairs, and then 
fuse these pairs together. When the compo- 
nent parts of an alloy are separately fused 
and mingled together, ~reat heat is evolved ; 
thus showing the chemical character of the 
union. 

The specific gravity of an alloy is seldom 
the mean of its constituents. In some cases 
there is an increase, and in others a diminu- 
tion of density. The following table, prepared 
by Thenard, shows clearly this peculiarity: 



Increased Density. 

Gold and Zinc. 

Gold and Tin. 

Gold and Bismuth. 

Gold and Antimonr. 

Gold and Cobalt. 

Silver and Zinc. 

Silver and Tin. 

Silver and Lead. 

Silver and Bismuth. 

Silver and Antimony. 

Copper and Zinc. 

Copper and Tin. 

Copper and Palladium. 

Copper and Bismuth. 

Copper and Anrimony. 

Lead and Bismuth. 

Load and Antimony. 

Plat in am and Molybdenum, 

Palladium and Bismuth. 



Decreased Density. 

Gold and Silver. 
Gold and Iron. 
Gold and Lead. 
Gold and Copper. 
Gold and Iridium. 
Gold and Nickel. 
Silver and Copper. 
Copper and Lead. 
Iron and Bismuth. 
Iron and Antimony. 
Iron and Lead. 
Tin and Lead. 
Tin and Palladium. 
Tin and Antimony. 
Nickel and Arsenic. 
Zinc and Antimony. 



Alloys conduct heat and electricity less per- 
fectly than the pure metals of which they are 
composed, and are generally less ductile than 



the more ductile of their constituents. "When 
formed by nearly equal proportions, there are 
as many ductile as brittle alloys ; but when 
one of the metals of an alloy greatly predom- 
inates, it is usually ductile. By combining 
ductile metals with brittle ones, brittle alloys 
are usually formed, if the brittle metal pre- 
dominates. All alloys of brittle metals are 
themselves brittle. 

Lead, tin, or zinc, when alloyed with the 
less fusible metals — copper, gold, and silver — 
produce alloys less malleable when cold than 
the superior metals, and, when heated barely 
to redness, fly in pieces under the hammer. 
Hence brass, gun-metal, etc., when hot, re- 
quire cautious treatment. 

The strength or cohesion of alloys is gen- 
erally greatly superior to that of their con- 
stituents. The relative weights required to 
sunder a bar one inch square of each of the 
following alloys is given in the following 
tables fi'om Muschenbroek's Investigations : 

Strength of Alloys. 

10 Copper— 1 Tin 32,093 lbs. 

8 " 1 " 36,088 " . 

6 " 1 " 44,071 " 

4 " 1 " 35,739 " 

2 " 1 " 1,017 " 

1 " 1 " 725 " 

Strength of the Cast Metals of zohich these Alloys were 
Composed. 

Barbary Copper 22,570 lbs. 

Japan " 20,272 " 

English Block Tin 6,650 " 

Banca " " ..'."'...'.'.'.'.!!!! 3',679 " 
Malacca " " 3,211 " 

These results show that theory and prac- 
tice agree in assigning the proportion of six 
to one as the strongest alloy. In the follow- 
ing alloys, which are the strongest of their 
respective groups, the tin is always four times 
the quantity of the other metal ; and they all 
confirm the remarkable fact, that alloys for 
the most part have a greater degree of cohe- 
sion than the stronger of their constituents. 

Strength of Alloys. 

4 English tin, 1 Lead 10,607 lbs. 

4 Banca tin, 1 Antimony, 13,480 " 

4 Banca tin, 1 Bismuth, 16.692 " 

4 English tin, 1 Zinc, 10,258 " 

4 English tin, 1 Antimony, 11,323 " 

Strength of their Constituent Cast Metals . 

, Lead, 885 lbs. 

Antimony, 1,060 " 
Zinc, 2,689 " 

Bismuth, 3,008 " 
Tin, 2,211 to 6,660 " 



186 



AMERICAN HOROLOGICAL JOURNAL. 



All the metals, even the most refractory, 
which can scarcely be fused in a crucible at 
the greatest heat of a furnace, melt down with 
ease when surrounded by more fusible ones. 
Thus nickel is nearly as difficult of fusion as 
iron, but it is usefully employed with copper 
in forming German silver, to which it gives 
whiteness and hardness. Platinum is a very 
refractory metal, yet it combines so readily 
with zinc, tin, and arsenic, that it is danger- 
ous to heat one of those metals in a platinum 
spoon, for an alloy would probably be formed 
and the spoon spoiled. 

This peculiarity fully explains the result 
which often occurs by the unskilful use of the 
blow-pipe. Any attempt to hard-solder gold 
or silver to which the smallest particle of 
lead, tin, zinc, or other easily fusible metal is 
attached, " eats up," as the workmen say, the 
gold or silver — that is, the superior metal, 
being in the presence of an easily fused one, 
commences to flow, and forms with the softer 
one an alloy which is exceedingly brittle and 
hard ; when intense heat is used, it sometimes 
becomes so hard as to resist the file. 

As we do not propose to give a treatise on 
metallurgy, only so far as of interest to the 
trade, and as not one simple metal enters into 
the construction of either clocks or watches, 
we shall be obliged to treat principally of 
alloys, the primary metals being spoken of 
only in their connection with them. 

Alloys are, without exception, more fusible 
than their constituent metals ; the fusing 
point of an alloy being generally lower than 
that of the less fusible metal in its com- 
position. An alloy, very remarkable for its 
easy fusibility, is formed of 8 parts bismuth, 5 
of lead, and 3 of tin, and fuses at about 200°. 
And yet, if we calculate the fusing point by 
multiplying the mean of the fusing points 
into their mass, we get 520° as the fusing point. 
8 X 500 + 5 X 600 + 3 X 422 



16 



= 520°. 



Safety plugs for steam-boilers are made by 
combining these metals in such proportions 
as to be fusible at a given temperature, and 
inserted in the hole in the boiler, and when 
the temperature arrives at the given degree, 
the plug is fused, giving escape to the steam, 
and relief to the pressure in the boiler. Sir 
Isaac Newton is said to be the discoverer of 



this fusible alloy. An alloy of antimony and 
iron can be set on fire by the action of a file. 
The alloy of chromium and lead will spon- 
taneously ignite in the open air if the tem- 
perature be slightly raised. In forming an 
alloy it is often necessary to protect one or 
both the metals from the action of the atmos- 
phere. Thus in combining lead and tin, resin 
or grease is usually put on the surface of the 
melted metals. In alloys formed of two 
metals, one of which is oxidizable and the 
other not, the first may be converted into an 
oxide, and the other retain its metallic stata 
By this method silver is separated from lead, 
and some of our native leads are sent to 
Europe for teatment by this method, the 
silver obtained making the transaction com- 
mercially profitable. 



HINTS TO REPAIRERS. 



In the practice of watch repairing there are 
many little appliances, and certain methods 
of performing various little jobs of work, the 
object of which is, in some instances, to save 
time and labor, and in others to impart a 
more perfect finish to the work. These little 
" secrets " { don't misunderstand the term), 
which to the accomplished workman would 
seem too insignificant to mention, would be 
more prized by the unskilled artisan than the 
most elaborate scientific essay on any subject 
connected with the manufacture of watches. 
To the workman whose occupation is that of 
a repairer only, any little assistance in the 
direction of saving time or labor is eagerly 
welcomed. 

A trouble much experienced by unskilled 
workmen, after replacing a broken cylinder 
or staff, is to find the proper place for the 
hair-spring stud in order to effect the proper 
beat. They manage to find it, it is true, but 
only after the expenditure of much time and 
labor, pushing the collet hither and thither 
until the proper " beat " is effected. In the 
case of a cylinder much time may be saved by 
putting the balance-wheel and bridge in posi- 
tion, being careful to screw down the bridge 
firmly to prevent shaking— a trouble often 
experienced with worn watches ; the balance 
is then moved to such a position that a tooth 



AMERICAN HOROLOGICAL JOURNAL. 



187 



of the escape-wheel rests on one of the im- 
pulse arms of the cylinder, it being imma- 
terial which, and the point on the balance 
exactly opposite the stud hole will be the pro- 
per place for the hair-spring stud. 

In a lever escapement the proper place for 
the stud is found by placing the balance in 
such a position that the ruby pins stand di- 
rectly in the centre, between the two banking 
pins or abutments, and the point on the 
balance exactly underneath or opposite the 
stud hole is the proper place for the hair- 
spring stud. This brings a tooth of the 
escape-wheel on one of the impulse planes of 
the pallet, which is the proper position. In 
general, the lever or cylinder escapement must 
be so adjusted that, when power is applied 
(wound), it will start of itself, without being 
shaken to bring it into action. In the Duplex 
escapement the proper place for the stud may 
be found by placing the balance in such a posi- 
tion that a long tooth of the escape-wheel rests 
on the duplex roller, exactly between the slot 
and impulse pallet ; the point on the balance- 
wheel exactly opposite the stud hole in the 
bridge being the proper place for the stud. The 
impulse jewel, when in action, should be 5° in 
front of the impulse tooth before receiving the 
impulse. The diameter of the duplex roller 
should be one-fourth the space between two 
long teeth of the escape-wheel. In the case of a 
chronometer escapement, the proper place for 
the stud is found by placing the balance in 
such a position that the gold spring is exactly 
between the impulse and unlocking jewels ; 
in such a position the point on the bal- 
ance directly opposite the stud hole is the 
proper place for the stud. The impulse 
jewel, when in action, should be 5° in front of 
the tooth before receiving the impulse. The 
chronometer and duplex escapements, unlike 
the lever and cylinder, require to be put in posi- 
tion to perform. This arises from the nature of 
the escapement. To underturn the face of a 
pinion, staff, etc., nicely, should be an object of 
solicitude to every repairer, as it gives a beauti- 
ful appearance to the finished work ; but to 
some workmen underturning presents many 
difficulties. The easiest manner of accomplish- 
ing this is by constructing a graver whose face, 
when ground, presents the shape of an acute 
cone, and which must be well hardened and 



tempered. The graver is then held in the 
position as if a point were to be turned in the 
direction of the underturning, which will 
effect the desired result. Care must be taken 
not to press the graver too hard against the 
object to be turned, as the point of the graver 
(the essential part) would be in danger 
of breaking, but should be held gently, yet 
firm. After grinding any graver it should 
be polished by rubbing it across a piece of 
chamois leather, stretched on a piece of wood, 
and impregnated with rouge. Any metal 
(unless it be too hard), especially brass, on 
being turned with a graver thus prepared, 
presents the part turned with the appearance 
of having been polished. 

It is very often necessary for the repairer 
to replace a hair-spring, and although this 
is not a very difficult job, it generally 
occupies the unskilled workman the greater 
portion of the day. By observing the follow- 
ing directions any workman will be enabled, 
with a little practice, to adjust a hair-spring 
suitable to the watch in the space of a quarter 
of an hour : First, ascertain the number of 
vibrations the balance makes in a minute, 
by counting the wheel teeth and pinion leaves, 
as explained on page 19, current volume. 
Generally, Swiss watches beat 300, English 
240, and American either 300 or 270 per 
minute ; secondly, select a spring whose outer 
coil lies naturally in the regulator pins at the 
same time that the inner coil is opposite the 
cock jewel, and temporarily fasten it to the 
balance staff with wax, and pin the outer coil 
into the stud, and place the balance thus into 
position. Wind the watch one turn, and allow 
it to vibrate exactly a minute, as indicated by 
a good regulator. Should the number of 
beats the balance makes in this minute 
coincide with the number of beats the watch 
ought properly to make, as before determined, 
then the spring is one well adapted to the 
watch ; but should it lose or gain vibrations 
in the minute indicated by the regulator, it 
proves the spring to be either too weak or too 
strong, and must be replaced by one suitable. 
It is not always necessary to change a spring 
should the difference be slight, as it may be 
regulated by giving greater length to, or short- 
ening the length of, the hair-spring. 

Charles Spiro. 



188 



AMERICAN HOROLOGICAL JOURNAL. 



LIGHT. 



NUMBER THREE. 



Before proceeding farther, it is necessary 
that these simple details should be thor- 
oughly mastered. Given the position of a 
point in the axis of a concave mirror, no diffi- 
culty must be experienced in finding the 
position of the image of that point, nor in 
determining whether the focus is virtual or 
real. It will thus become evident that while a 
point moves from an infinite distance to the 
centre of a spherical mirror, the image of that 
point moves only over the distance between 
the principal focus and the centre. Con- 
versely, it will be seen that during the pas- 
sage of a luminous point from the centre to 
the principal focus, the image of the 
point moves from the centre to an 
infinite distance. The point and its image 
occupy what are called conjugate foci. If the 
last note be understood, it will be seen that 
the conjugate foci move in opposite direc- 
tions, and that they coincide at the centre of 
the mirror. If, instead of a point, an object 
of sensible dimensions be placed beyond the 
centre of the mirror, an inverted image of the 
object diminished in size will be formed 
between the centre and the principal focus. 

If the object be placed between the centre 
and the principal focus, an inverted and mag- 
nified image of the object will be formed 
beyond the centre. The positions of the 
image and its object are, it will be remem- 
bered, convertible. In the two cases men- 
tioned in the preceding paragraph, the image 
is formed in the air in front of the mirror. It 
is a real image. But if the object be placed 
between the principal focus and the mirror, 
an erect and magnified image of the object is 
seen behind the mirror. The image is here 
virtual. The rays enter the eye as if they 
came from an object behind the mirror. It 
is plain that the images seen in a common 
looking-glass are all virtual images. 

It is now to be noted that what has been 
here stated regarding the gathering of rays to 
a single focus by a spherical mirror is only 
true when the mirror forms a small fraction 
of the spherical surface. Even then it is only 



* Extracts from Prof. Tyndall's lectures on Light. 



practically, not strictly and theoretically, 
true. 

CAUSTICS BY REFLECTION (cATACAUSTICs). 

When a large fraction of the spherical sur- 
face is employed as a mirror, the rays are not 
all collected to a point ; their intersections, 
on the contrary, form a luminous surface, 
which in optics is called a caustic (German, 
Brennflache). The interior surface of a com- 
mon drinking-glass is a curved reflector. Let 
the glass be nearly filled with milk, and a 
lighted candle placed beside it ; a caustic 
curve will be drawn upon the surface of the 
milk. A carefully bent hoop, silvered within, 
also shows the caustic very beautifully. The 
focus of a spherical mirror is the cusp of its 
caustic. 

Aberration. — The deviation of any ray from 
this cusp is called the aberration of the ray. 
The inability of a spherical mirror to collect 
all the rays falling upon it to a single point is 
called the spherical aberration of the mirror. 

Real images, as already stated, are formed 
in the air in front of a concave mirror, and 
they may be seen in the air by an eye placed 
among the divergent rays beyond the image. 
If an opaque screen, say of thick paper, inter- 
sect the image, it is projected on the screen 
and is seen in all positions by an eye placed in 
front of the screen. If the screen be semi- 
transparent, say of ground glass or tracing- 
paper, the image is seen by an eye placed 
either in front of the screen or behind it. 
The images in phantasmagoria are thus 
formed. 

Concave spherical surfaces are usually 
employed as burning-mirrors. By condens- 
ing the sunbeams with a mirror 3 feet in 
diameter and of 2 feet focal distance, very 
powerful effects may be obtained. At the 
focus, water is rapidly boiled, and combusti- 
ble bodies are immediately set on fire. Thick 
paper bursts into flame with explosive vio- 
lence, and a plank is pierced as with a hot 
iron. 

CONVEX MIRRORS. 

In the case of a con vex spherical mirror the 
positions of its foci and of its images are 
found as in the case of a concave mirror. But 
all the foci and all the images of a convex 
mirror are virtual. Thus to find the princi- 
pal focus you draw parallel rays, which, on 



AMEKICAN HOROLOGICAL JOURNAL. 



189 



reflection, enclose angles with the radii equal 
to those enclosed by the direct rays. The 
reflected rays are here divergent ; but on 
being produced backwards, they intersect at 
the principal focus behind (he mirror. 

The drawing of two lines suffices to fix the 
position of the image of any point of an 
object either in concave or convex spherical 
mirrors. A ray drawn from the point through 
the centre of the mirror will be reflected 
through the centre ; a ray drawn parallel to 
the axis of the mirror will, after reflection, 
pass, or its production will pass, through the 
principal focus. The intersection of these 
two reflected rays determines the position of 
the image of the point. Applying this con- 
struction to objects of sensible magnitude, it 
follows that the image of an object in a con- 
vex mirror is always erect and diminished. 

If the mirror be parabolic instead of spher- 
ical, all parallel rays falling upon the mirror 
are collected to a point at its focus ; con- 
versely, a luminous point placed at the focus 
S3nds forth pira'lel rays ; there is no aber- 
ration. If the mirror be elliptical, all rays 
emitted from one of the foci of the ellipsoid 
are collected together at the other. Para- 
bolic reflectors are employed in light-houses, 
where it is an object to send a power- 
ful beam, consisting of rays as nearly as 
possible parallel, far out to sea. In this case 
the centre of the flame is placed in the focus 
of the mirror ; but, inasmuch as the flame is 
of sensible magnitude, and not a mere point, 
the rays of the reflected beam are not accu- 
rately parallel. 

T3P, REFRACTION OF LIGHT ( DIOPTRICS ). 

"We have hitherto confined our attention to 
the portion of a beam of light which rebounds 
from the reflecting surface. But, in general, 
a portion of the beam also enters the reflect- 
ing substance, being rapidly quenched when 
the substance is opaque, and freely transmit- 
ted when the substance is transparent. Thus 
in the case of water, when the incidence is 
perpendicular, all the rays are transmitted, 
save the 18 referred to as being reflected. 
That is to say, 982 out of every 1,000 rays 
enter the water and pass through it. So 
likewise in the case of mercury, mentioned 
in the :-;ame note; 334 out of every 1,000 rays 
falling on the mercury at a perpendicular 



incidence, enter the metal and are quenched 
at a minute depth beneath its surface. 

We have now to consider that portion of 
the luminous beam which enters the reflect- 
ing substance, taking, as an illustrative case, 
the passage from air into water. If the beam 
fall upon the water as a perpendicular, it 
pursues a straight course through the water; 
if the incidence be oblique, the direction of 
the beam is changed at the point where it 




enters the water. This bending of the beam 
is called refraction. Its amount is different 
in different substances. The refraction of 
light obeys a perfectly rigid law which must 
be clearly understood. Let A B C D, Fig. 2, 
be the section of a cylindrical vessel which is 
half filled with water, its surface being A C. 
E is the centre of the circular section of the 
cylinder, and B D is a perpendicular to the 
surface at E. Let the cylindrical envelope of 
the vessel be opaque, say of brass or tin, and 
let an aperture be imagined in it at B, through 
which a narrow light-beam passes to the 
point E. The beam will pursue a straight 
course to D without turning to the right or 
to the left. Let the aperture be imagined at 
m, the beam striking the surface of the water 
at E obliquely. Its course on entering the 
liquid will be changed ; it will pursue the 
track E n. Draw the line m o perpendicular 
to B D, and also the line n p perpendicular to 
the same B D. It is always found that m o 
divided by n p is a constant quantity, no matter 
what may be the angle at which the ray 
enters the water. The angle marked x above 
the surface is called the angle of incidence ; 
the angle at y below the surface is called the 
angle of refraction ; and if we regard the 
radius of the circle A B C D as uni y or 1, the 
line m o will be the sine of the angle of inci- 



190 



AMERICAN HOROLOGICAL JOURNAL. 



dence; while the line n p will be the sine of 
the angle of refraction. Hence the all-im- 
portant optical law — The sine of the angle of 
incidence divided by the sine of the angle of re- 
fraction is a constant quantity. However these 
angles may vary in size, this bond of relation- 
ship is never severed. If one of them be 
lessened or augmented, the other must dimin- 
ish or increase, so as to obey this law. Thus, 
if the incidence be along the dotted line m' E, 
the refraction will be along the line E n', but 
the ratio of m' o' to n' p' will be precisely the 
same as that of mo ton p. The constant quan- 
tity here referred to is called the index of re- 
fraction. 

One word more is necessary to the full 
comprehension of the term sine, and of the 
experimental demonstration of the law of 
refraction. When one number is divided 
by another, the quotient is called the ratio of 
the one number to the other. Thus 1 divi- 
ded by 2 is | 3 and this is the ratio of 1 to 2. 
Thus also 2 divided by 1 is 2, and this is the 
ratio of 2 to 1. In like manner 12 divided by 
3 is 4, and this is the ratio of 12 to 3. Con- 
versely, 3 divided by 12 is \, and this is the 
ration of 3 to 12. In a right-angled triangle 
the ratio of any size to the hypothenuse is 
found by dividing that side by the hypothe- 
nuse. The ratio is the sine of the angle opposite 
to the side, however large or small the triangle 
may be. Thus in Fig. 2 the sine of the angle 
x in the right-angled triangle E o m, is really 
the ratio of the line o m to the lrypothenuse 
E m ; it would be expressed in a fractional 



form thus, 



E?n 



In like manner, the sine of 



y is the ratio of the line n p to the hypothe- 
nuse E n, and would be expressed in a frac- 
n p 



tional form thus, 



E n 



These fractions are 



the sines of the respective angles, whatever 
be the length of the line E m or E n. In the 
particular case above referred to, where these 
lines are considered [as units, the fractions 

— - and — -' or, in other words, m o and np 

become, as stated, the sines of the respective 
angles. We are now prepared to understand 
a simple but rigid demonstration of the law 
of refraction. 

M L J K is a cell with parallel glass sides 



and one opaque end, M L. The light of a 
candle placed at A falls into the vessel, the 




end M L casting a shadow which reaches to 
the point E. Fill the vessel with water — the 
shadow retreats to H through the refraction 
of the light at the point where it enters the 
water. The angle enclosed between M E 
and M L is equal to the angle of incidence 
x, and in accordance with the definition 

T "F T FT 

given in 120, ; — — is its sine: while — — : is the 
° ME M H 

sine of the angle of refraction, y. All these 
lines can be either measured or calculated. 
If they be thus determined, and if the divi- 
sion be actually made, it will always be found 

T "F T FT 

that the two quotients — - and — — stand in 
1 ME M H 

a constant ratio to each other, whatever the 
angle may be at which the light from A strikes 
the surface of the liquid. This ratio in the 
case of water is f, or, expressed in decimals, 
1.333. When the light passes from air into 
water, the refracted ray is bent toivards the 
perpendicular. This is generally, but not 
always, the case when the light passes from 
a rarer to a denser medium. The principle 
of reversibility which runs through the whole 
of optics finds illustration here. When the 
ray passes from water to air it is bent from 
the perpendicular; it accurately reverses its 
course. If instead of water we employed vine- 
gar, the ratio would be 1.344; with brandy it 
would be 1.360; with rectified spirit of wine, 
1.372; with oil of almonds or with olive oil, 
1.470; with spirit of turpentine, 1.605; with 
oil of aniseed, 1.538; with oil of bitter almonds, 
1.471; with bisulphide of carbon, 1.678; with 
phosphorus, 2.24. These numbers express 
the indices of refraction of the various sub- 
stances mentioned; all of them refract the 
light more powerfully than water, and it is 
worthy of remark that all of them, except 
vinegar are combustible substances. 



AMERICAN HOEOLOGICAL JOURNAL. 



191 



It was the observation on the part of New- 
ton, that, having regard to their density, 
"unctuous substances " as a general rule re- 
fracted light powerfully, coupled with the 
fact that the index of refraction of the dia- 
mond reached, according to his measure- 
ments, so high a figure as 2.439, that caused 
him to foresee the possible combustible na- 
ture of the diamond. The bold prophecy of 
Newton has been fulfilled, the combustion of 
a diamond being one of the commonest ex- 
periments of modern chemistry. It is here 
worth noting that the refraction by spirit of 
turpentine is greater than that by water, 
though the density of the spirit is to that of 
the water as 874 is to 1,000. A ray passing 
obliquely from the spirit of ti rpentine into 
water is bent from the perpendicular, though 
it passes from a rarer to a denser medium; 
while a ray passing from water into the spirit 
of turpentine is bent towards the perpendicular, 
though it passes from a denser to a rarer 
medium. Hence the necessity of the words 
"not always," employed in 123. 

If a ray of light pass through a refracting plate 
with parallel surfaces, or through any nunber 
of plates with parallel surfaces on regaining 
the medium from which it started, its original 
direction is restored. This follows from the 
principle of reversibility already referred to. 
In passing through a refracting body, or 
through any number of refracting bodies, the 
light accomplishes its transit in the minimum 
of time. That is to say, given the velocity of 
light in the various media, the path chosen 
by the ray, or, in other words, the path which 
its refraction imposes upon the ray, enables 
it to perform its journey in the most rapid 
manner possible. Refraction always causes 
water to appear shallower, or a transparent 
plate of any kind thinner, than it really is. 
The lifting up of the lower surface of a glass 
cube, through this cause, is very remarkable. 
To understand why the water appears 
shallower, fix your attention on a point at its 
bottom, and suppose the line of vision from 
that point to the eye to be perpendicular to 
the surface of the water. Of all rays issuing 
from the point, the perpendicular one alone 
reaches the eye without refraction. Those 
close to the perpendicular, on emerging from 
the water, have their divergence augmented 



by refraction. Producing these divergent 
rays backwards, they intersect at a point 
above the real bottom, and at this point the 
bottom will be seen. The apparent shallow- 
ness is augmented by looking obliquely into 
the water. In consequence of this apparent 
rise of the bottom, a straight stick thrust 
into water is bent at the surface from 
the perpendicular. Note the difference 
between the deportment of the stick and of a 
luminous beam. The beam on entering the 
water is bent towards the perpendicular. This 
apparent lifting of the bottom when water is 
poured into a basin brings into sight an ob- 
ject at the bottom of the basin which is un- 
seen when the basin is empty. 



ANSWERS TO CORRESPONDENTS. 



P. G., Mass., inquires, with some anxiety, 
whether the eyes of a watchmaker are not 
liable to injury by the constant and intense 
use of them in his occupation. We think 
not. Observations among the fraternity in 
this respect have convinced us — and we 
think the observation of all will confirm the 
opinion — that the eyes of watchmakers will 
compare favorably with any class of me- 
chanics or tradesmen in durability ; indeed, 
if there be any difference, their eyes are 
better. 

The injury to eyes is not usually done by 
intense use of them, but by tiresome use. With 
a watchmaker, for a moment or two — or at 
farthest for five minutes — he may apply them 
intensely ; then they are relieved from strain 
by a look out of the window, across the shop, 
at a customer, or whatever else, and become 
rested. But let them be fixed — set, as it 
were, to a given focal distance, as in reading, 
sewing, writing, or any occupation that con- 
fines them for hours to that one distance — 
and they will become painful, and demand 
relief, which, if denied, will sooner or later 
tell upon their healthy condition. The use of 
an eye-glass for years should, if injurious, 
show that injury by some difference in the 
two eyes ; but facts show no such difference, 
although the glass may have been used on 
one eye only for very many years. P. G. 



192 



AMERICAN HOROLOGICAL JOURNAL. 



need have no misgivings about the failure of 
his sight from any such cause. 

G. M. H, N Y — The instrument of which 
you send a drawing is by no means new, 
being found in all the tool stores, and known 
as an inside caliper. 

Your use of it is new, but we cannot see in 
what way it will be very beneficial ; as we 
understand your description, you only get the 
distance between the shoulders of the pinion 
or staff, and that measurement is seldom lost, 
for pinions very rarely break. If the pivot 
breaks you still have the shoulder left, and 
your tool would be useless. A staff never 
breaks, only the pivots; and your caliper will 
rot give you the length of the required pivot. 
If the points of your instrument were small 
enough to go through the jewel hole and rest 
against the end stone, they would be too 
delicate to handle with safety. 

H. E. W., Richfield Springs.— Muck of the 
Etruscan jewelry is made so exceedingly thin 
as to be almost destroyed by the process of 
coloring. No quality finer than 14 carat can 
be used for such a purpose, the coloring being 
done by eating away, chemically, the alloy 
from the surface, leaving only the fine gold; 
and as this takes effect on both surfaces, 
when very thin, there is no solid metal left 
for strength, and consequently the article is 
exceedingly fragile. 

When such goods are hard-soldered the 
color cannot be restored except by gilding, 
coloring it b} r the battery process ; sometimes 
in cases of exigency, when soft-soldering 
must be resorted to, a temporary color can be 
applied by painting the discolored part with 
shell gold. 

AMERICAN HOROLOGICAL JOURNAL, 

PUBLISHED MONTHLY BY 

229 Broadicay, X. T., 
At $2.50 per Year, payable in advance. 

A limited '-number of Advertisements connected 
with the Trade, and from reliable Houses, will be 
rteeived. 

fcstr Mr. J. Herrmann, 21 Northampton 
Square, E. C, London, is our authorized Agent 
for Greet Britain. 
All communications should be addressed, 
G. B. MILLER, 
P. 0. Box 6715, New York. 



EQUATION OF TIME TABLE. 



GREENWICH MEAN TIME. 



For February, 1871. 



(V 




Sidereal 
Time 


Equation 


Equation 




Sidereal 


Is 


Day 


of 
the 8emi- 


of 
Time to be 


of 
Time to be 


Diff. 


or 

Right 

Ascension 

of 




Mon. 


diameter 
Passing 


Added to 
Apparent 


Subtracted 
from 


One 






the 
Meridian. 


Time. 


Mean Time. 




Mean Sun. 






S. 


M. 8. 


M. 8. 


8. 


H. M. 8. 


w 


1 


68.28 


13 49 81 


13 49 73 


0.332 


20 45- 0.24 


Th 


7, 


68.17 


13 57.33 


13 57 26 


0.297 


20 48 56.80 


Fri 


3 


68.05 


14 4.02 


14 3 96 


0.262 


20 52 53.36 


Sat 


4 


67 94 


14 9.89 


14 9 84 


0.227 


20 56 49.91 


Su, 


5 


67 82 


14 14.94 


14 14 89 


0.193 


21 46.47 


M.. 


6 


67.71 


14 19.17 


14 19 13 


0.159 


21 4 43.02 


Th. 


7 


67.59 


14 22.60 


14 22 57 


0.126 


21 8 39.58 


W. 


8 


67 48 


14 25.25 


14 25.23 


0.094 


21 12 36.13 


Th 


9 


67 36 


14 27.12 


14 27.10 


0.062 


21 16 32.69 


Fri 


10 


67.25 


14 28.21 


14 28.20 


0.030 


21 20 29.24 


Sat, 


11 


67.14 


14 28.53 


14 28 53 


0.001 


21 24 25.80 


Su. 


12 


67 03 


14 28.11 


14 28.12 


0.032 


21 28 22.35 


M.. 


13 


66 92 


14 26.95 


14 26.97 


0.063 


21 32 18.90 


Tn. 


14 


66 81 


14 25 06 


14 25.08 


0.093 


21 36 15.46 


W. 


15 


66.71 


14 22.45 


14 22 48 


0.123 


21 40 12.01 


Tli. 


16 


66 61 


14 19.12 


14 19.16 


0.153 


2144 8.57 


Fri. 


17 


66.51 


14 15.10 


14 15.14 


0.182 


21 48 5.12 


Sat 


18 


66 41 


14 10.37 


14 10.42 


0.211 


21 52 1.67 


Su 


19 


66.31 


14 4 95 


14 5.00 


0.239 


21 55 58.23 


M.. 


20 


66 21 


13 5^.85 


13 58.92 


0.267 


21 59 54.78 


Tu. 


21 


66.12 


13 52.09 


13 52 16 


0.294 


22 3 51.34 


W. 


22 


66.02 


13 44 68 


13 44 76 


0.321 


22 7 47.89 


Th. 


23 


65.93 


13 36.04 


13 36.73 


0.348 


22 11 44.44 


Fri 


24 


65.84 


13 27.96 


13 28.05 


0.375 


22 15 41.00 


Sat 


25 


65.76 


13 18.66 


13 18.75 


0.400 


22 19 37 55 


Su. 


26 


65.68 


13 8.76 


13 8.86 


0.424 


22 23 34.10 


M. 


27 


65 60 


12 58.28 


12 58.37 


0.448 


22 27 80.66 


Tu. 


28 


65.52 


12 47.21 


12 47 32 


0.471 


22 31 27.21 



Mean time of the Semidiameter passing may be found by sub- 
tracting 0.19 s. from the sidereal time. 

The Semidiameter for mean neon may be assumed the same as 
that for apparent noon. 

PHASES OF THE MOON. 

D H. M. 

© Full Moon 5 2 2.0 

( Last Quarter... 12 3 0.4 

New Moon 19 149 

) FirstQuarter 26 22 38.3 

D. H. 

( Perigee 13 7 1 

( Apogee 26 9.2 

O I II 

Latitude of Harvard Observatory 42 22 48.1 

h. m. s. 

Long. Harvard Observatory 4 44 29 . 05 

New York City Hall 4 56 0.15 

Savannah Exchange 5 24 20 . 572 

Hudson, Ohio ... 5 25 43.20 

Cincinnati Observatory 5 37 58.062 

Point Conception 8 142.64 

APPABENT APPABENT MERID. 

B. ASCENSION. DECLINATION. PA8SAQB. 

D. H. M. 8. o • H - M ' 

Venus 1 21 52 45. 81.... -14 28 8.4 1 7.8 

Jupiter.... 1 5 1 36 14.. ..4 22 25 45.2 8 15.2 

Saturn. .. 1 18 23 63.72.... -22 32 8.3 2135.7 



AMERICAN 



Horolosical Journal. 



Vol. II. 



NEW YORK, MARCH, 1871 



No. 9. 



CONTENTS. 

Essay on* the Construction of a Simple and 

Mechanicallt Perfect Watch, • 193 

Correction, 200 

Heat 201 

Bkass Allots, 204 

Light, 207 

Hi>-ts to Repairers, 211 

Good Time 212 

Donation- to the Museum of the Land Office, . 213 

Jewelry Peddlers 213 

Qcery, 214 

Answers to Correspondents.. . . %. . . . 215 

Equation of Time Taf,lb 216 

* » * Address all communications for Horological 
Journal to G. B. Mlllek, P. 0. Box 6715, New York 
City. Publication Office 229 Broadway, Room 19. 

[Entered according to Act of Congress, by G. B. Miller, in tbe 
office of tha Librarian of Cougress at Washington.] 

ESSAY 

ON TUB 

CONSTRUCTION OF A SIMPLE AND MECHANI- 
CALLY PERFECT WATCH. 



BY MOKRITZ GROSSMANN. 



CHAPTER II. 

THE BARREL AND MATN-BPRING. 

24. An attentive consideration of tbe way 
in -which this element of the -watch is exe- 
cuted by the modern horological manufac- 
turers will result in the conviction that the 
care which is due to an object 
of such importance has not been 
bestowed upon it. This fact is 
the more surprising, as a great 
number of cheap lever watches 
are produced in our day, with 
escapements so badly made that 
they can only be brought to a 
tolerable vibration by an excess 
of motive power. 

25. In arra- ging the barrel 
of a watch, the manufacturer 
ought to be thoroughly penetrated with the 
principle that the height and diameter 
granted for a watch should determine the 
breadth and thickness of the main -spring. 
It is of the utmost importance to make the 



barrel as high and wide as the dimensions of 
the watch will allow of. For this purpose it 
will prove a good proportion to multiply the 
outer diameter of the pillar plate by the frac- 
tion 0.47. This will be the diameter of a 
barrel wheel as large as the size of the watch 
will admit (Fig. 1a). It is even possible to 
go a little beyond this limit, by placing the 
toothed part of the barrel a little lower than 
it is commonly done, in order* to lodge this 
largest part of the barrel in the hollow space 
of the middle rim of the case, where there is 
always space enough, especially in hunting 
cases, if the case springs are properly placed 
(Fig. 1b). In this case, the diameter of the 
plate may be multiplied by 0.485, for attain- 
ing the diameter of the barrel. 

26. The height of the barrel in a three- 
quarter plate movement ought to be the sum 
of the height of the pillars and the thickness 
of the pillar plate, after subtracting only a 
sufficient space for the free movement be- 
tween the top and bottom of the barrel and 
the frame plates, and the necessary thickness 
of the bearing for the lower end of the barrel 
arboi\ _•■ , 

Fig. 1a. 




27. It will be easily understood that a 

watch, the escapement and depths of which 

I are imperfect, and made in a careless way, 

! will require a powerful main-spring, while in 

! a carefully made watch, the judicious utilizing 



194 



AMERICAN HOROLOGICAL JOURNAL. 



of space in the barrel will allow of employing 
a long and thin main-spring, which, by its 

Fig. 1b. 




suppleness, is less liable to accident, and, by 
the number of turns it makes in the barrel, 
affords the advantageous resource of select- 
ing the middle turns of the development of 
the sprkig for the daily march of the move- 
ment, and thus to obtain a greater uniformity 
of motive power. 

28. It will also be found advisable to re- 
duce the breadth of the toothed rim of the 
barrel as nearly as possible to the amount 
required for the length of the teeth. There 
are many watches, the barrels of which, al- 
ready too small in diameter, have also the 
toothed rim of an excessive breadth, so that 
much of the space due to the spring is entirely 
lost. It is quite obvious that a barrel of that 
kind causes a double loss of power. Not 
only must the spring be thinner and weaker 
than it might otherwise be, but also the inner 
radius of the bar*%J , which is the lever of power, 
is shortened ; while the radius of the toothed 
part, which is the lever of resistance, is tke 
same. The same consideration indicates also, 
that the sides of the barrel ought only to 
have the thickness required for fastening a 
solid hook. 

29. If all the proportions of the barrel are 
as they ought to be, a spring of the thickness 
of -J ff of the inner diameter of the barrel will 
be quite sufficient to produce a lively vibra- 



tion in a, watch with escapement and depths 
a little carefully made- Such a spring, if the 
centre of the arbor is one-third of the inner 
diameter of the barrel, has a development 
of more than six turns, of 
which the middle ones may 
be selected for the daily 
march of the watch, 

30- The way in which to 
construct the barrel arbor 
shows a vast difference be- 
tween the various manu- 
facturing countries. I do 
not hesitate a single mo- 
ment to disapprove the sys- 
tem in general use in the 
Swiss watches. In the great- 
est part of them the lower 
end of the arbor has no 
bearing and support at all, 
and the barrel is maintained 
in its place by the ratchet, 
which is made out of the solid of the arbor. 
This system shows clearly that the preference 
which it enjoys is merely due to a blind 
routine. It offers neither economy of time 
in the manufacturing and in the repairing, 
nor a better distribution of room for flat 
watches ; besides, it is inferior in the point 
of solidity and durability. In all v/atches, in 
those of careful make as well as in those of 
lower class work, the barrel arbor ought to 
be supported at both ends by solid bearings ; 
in the former for the sake of greater solidity, 
and in the latter, also, for that of cheaper 
manufacturing. 

31. There are two modes of executing these 
free standing barrel arbors. One of them 
has the ratchet forming part of the arbor it- 
self (Fig. 2), sunk from the upper side into 
Fig. 2. 




the uuirel unuge, and is neid in its pi&uc oy 
a cap with three or four screws. These screws, 
having hardly more than three or four threads 



AMERICAN HOEOLOGICAL JOURNAL. 



195 



in the substance of the bridge, are the only 
means of securing the stability of the recep- 
tacle of the moving power in the watch; 
Every repairer will know, from oft-repeated 
experience, that th's adjustment is an inex- 
haustible source of trouble, and that the inner 
face of the cap or the bottom of the sink are 
subject to rapid wear by the daily winding, if 
it has been neglected to oil the frictional sur- 
faces. The consequence of this wear is an 
excess of shake of the ratchet and of the whole 
barrel. Any defect of this kind is a very 
serious one, because the barrel and centre- 
wheel, the two largest moving parts of the 
train, have, by necessity, their surfaces very 
close to each other. 

32. With the other mode of execution, the 
ratchet is screwed with three screws on to 
the shoulder formed at the part of the arbor 
just above the barrel (Fig. 3). 

This s- stem is still worse from the point 




of durability. There are only two small an- 
nular surfaces which constitute the hold of 
the barrel. The shoulder of the arbor, as 
well as the edge of the ratchet, wear away 
gradually the upper and lower side of the 
bridge, and the screws slacken their hold by 
the numerous little jerks of the click when 
winding the watch. Besides, the ratchet is 
subject to defects in hardening, and by the 
three holes and sinks for the serews rather 
close to the edge. In b<5th these cases iiw 
core of the barrel arbor is a separate piece, 
screwed on the arbor, or adjusted on it and 
held in its place by a pin through both parts. 
The finger of the stop-work is secured to the 
end of the arbor by a pin through this latter. 



33. The most advantageous way, both for 
the manufacturing and repairing, as well as 
for the durability and good service, is to 
make the barrel arbor with two pivots, sup- 
ported each by a bearing. An arbor of this 
kind is very easy to execute. The ratchet 
must be fitted on the square of the arbor, 
which is easier to achieve than the adjustment 
of the core of the Swiss arbors. There is no 
necessity of perforating the lower end of the 
arbor in order to secure the stop-finger in 
its place, which is attained by the lower bridge 
of the barrel. 

A barrel of this nature is much easier to 
take to pieces and to put together than a 
Swiss one. It requires merely taking off the 
cover of the barrel, and all is done ; while 
with the other one the pin of the stop-finger 
must be taken off, and after opening the bar- 
rel, the pin joining the core to the arbor must 
be drawn out or the core screwed off, before 
the parts can be cleaned, or a new spring 
put in, and afterwards 
all these arrangements 
have to be got together 
again. 

34. In a frame, the pillar 
plate of which was hollowed 
only 0.2 or 0.3 mill, at the 
dial side, this space would 
suffice for containing a thin 
steel bridge for maintaining 
the lower pivot of the arbor. 
The same space would be 
necessitated for receiving m 
a solid way the pin for the 
stop-finger, if we do not wish to create that 
unfortunate state of many flat watches, in 
which it is hardly possible to draw out and 
put in that pin without splitting the end of 
the arbor. Thus it wilj be seen that there is 
not even an economy of space to be obtained 
by this system. 

CHAPTER III. 

THE CLICK TTOKK. 

35. The click is a necessary adjunct of the 
barrel and main-spring, its purpose being to 
prevent the retrograde motion of the arbor 
when the winding action ceases. This func- 
tion being rather out of connexion with all 
the other parts of the movement, it cannot be 



196 



AMERICAN HOROLOGICAL JOURNAL. 



a matter of surprise to see the click-woi'k 
executed in a great variety of different ways, 
all attaining the same purpose with more or 
less ease in the execution, and with different 
degrees of elegance in appearance. 

36. If simplicity and easy execution are 
required — especially if the click-work is to be 
sunk into the upper plate — it seems that the 
round adjustments deserve the preference. 
The most simple click- work of that kind 
would consist in the ratchet and click-spring ; 
the latter of circular form, and surrounding 
the ratchet with only the necessary interval 
for free movement — both parts to be adjusted 
in a sink in the upper plate (Fig, 4j. The 

i Fig. 4. 




click ought to move on a stud left in the sink, 
or between two pivots. The whole arrange- 
ment would be covered and held in its place 
by a cap screwed on the plate, and perhaps 
sunk into it a trifle, just in order to centre it 
easier. A small hole through the cap, at a 
proper place, would be useful for lifting the 
click out of action when it is required to let 
the spring down. It would hardly be possi- 
ble to have a click-work more simple and 
cheap of execution, and still quite reliable, 
than this one. 

37. For watches, in the execution of which 



a greater degree of elegance is wished for, 
the click and click-spring may be exposed by 
leaving a small annular space round the sink 
that contains the ratchet, on which space the 
cap is screwed. The spring is lodged into a 
circular sink outside this space, so that it is 
only covered a very little by the cap, in order 
to be secured to its place (Fig. 5). The 

Fig. 5. 





thinner acting part of the spring may easily 
be formed in an eccentric chuck on the lathe. 

38. It would be 
Fig. 6. a simplification 

of the click-work 
to form the click 
at the acting end 
of the spring, but 
the click and 
spring are much 
exposed to break, 
and in such a case 
the replacing of 
the piece would 
be a greater 
trouble (Figs. 6 
and 7). 

39. The mate- 
rial of which the 
click-work ought 
to be made is 
hardened and 
well tempered 
steel, at least for 
the ratchet and 
click. The spring 

might as well be made of another metal of 
sufficient elasticity, but steel is generally pre- 
ferred, for the more lively appearance which 
its polished surface gives to the movement. 



Fig. 7. 




AMERICAN HOROLOGICAL JOURNAL. 



197 



CHAPTER IV. 



THE STOP-WOBK. 



40. The last of the accessories of the 
moving power is the mechanism regulating 
the amount of tension to apply to the spring 
in winding it, and the range of development 
of this latter to be employed for the daily 
march of the watch. This part, of all others, 
is the most open to controversy as to the 
best mode of attaining its purpose ; and as to 
the way of its execution there is a great va- 
riety, from its total omission to the rather 
complicated and ingenious stop-works of 
some Swiss and French watches. 

41. When we attempt to establish the rela- 
tive merits of those different constructions, 
there is an important feature which may 
guide our judgment. This is the friction ; 
and all stop-works whose parts move under 
the control of a frictional resistance, may be 
objected to; because friction, however slight 
it may be, if it can be avoided, is a useless 
loss of power. Besides, in all the stop-works 
of this kind, it is a tooth or finger only, 
which, by butting against the full part of the 
stop-wheel, puts an end to the winding. 
This tooth or finger is liable to break under 
the strain it may be subjected to by the care- 
less way in which many people wind their 
watches. 

42. The most common of these frictional 
stop-works, though not often seen in watch- 
work, has a wheel in which only three or 
four teeth are cut, and all the rest of the per- 
iphery left full. This wheel is screwed, with 
a stop-screw, to the plate, and the end of the 
barrel arbor carries a finger or tooth gearing 
into it, and moving one tooth of it at each 
revolution of the arbor. At the beginning 
and end of the winding range the tooth butts 
against the full part of the wheel's circum- 
ference, and prevents further motion of the 
arbor. It is evident that during all the time 
betwpen two passages of the tooth the stop- 
w heel is without any control whatever, and 
might move round its axis by any external 
shocks if the freedom of its motion was not 
chocked by a stiffening spring, causing suffi- 
cient friction. Sometimes the stop-wheel is 
reduced to a narrow rim, and is open at the 
place opposite the teeth, so that it is sprung 




on a little undercut stud spared from the 
substance of the barrel cover, thus gaining 
its hold without any screw or spring (Fig. 8). 
Fig. 8. 43. To the same 

class belongs a 
kind of stop-work, 
forming, as it were, 
an inward gear. 
A concentric an- 
nular groove is 
cut into the barrel cover, a little undercut 
at its outer edge. This groove holds an an- 
nular spring, in the inner edge of which 
some teeth are cut in which the stop-finger 
is to gear, and to limit the winding by coming 
into contact with the plain part of the spring. 
The friction of this latter in its groove pre- 
vents any untimely movement. It is obvious 
that this arrangement is liable to the same 
objections as the former one (Fig. 9). 

Fig. 9. 44. Of the 

other class of 
stop-works, ope- 
rating without 
friction, we men- 
tion a very ju- 
dicious arrange- 
ment frequently 
met with in the 
better class' of 
Swiss and 
French watches 
of about fifty years of age. It consists of two 
small toothed wheels gearing into each other; 
the one on the barrel arbor having some 
teeth more than the other one, so that the 
same teeth of both wheels meet only after a 
certain number of turns allowed for the 
Fig. 10. winding. Both the wheels 

have on their upper side, 
fastened in a solid way, 
a stop-piece of steel, and 
these two stop-pieces, 
when meeting, stop the 
motion by butting in &• 
right angle (Fig. 10;. 
The mechanical perfec- 
tion, and the reliability 
of this stop-work is be- 
yond any doubt; and it 
only has the drawback that it requires an 
additional height for the stop-pieces placed 





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AMERICAN HOROLOGICAL JOUENAL. 




over tlie two wheels, aBd it is easy to find 
that by the same quantity the breadth of the 
main-spring must be restrained. 

Frr , 11 45. The stop -work 

with the cross of Malta 
(Fig. 11) is the most in 
use for watch-work, and 
deserves this preference. 
It is too well known to 
require a description. It 
is true that the careless 
way in which this stop- 
work is often executed, 
in the lower classes of 
watches, is a source of 
trouble and disappoint- 
ment, both to the wearers of the watches and 
to the repairers. It must be well under- 
stood that the Malta stop-work does not 
allo.v any meanness or neglect in its execu- 
tion; but, well executed, it has a solidity up 
to any proof. "With a judiciously arranged 
set of tools there is no great difficulty in man- 
ufacturing it in an irreproachable way. 

46. Still, the stop-work, however well it is 
made, is only an unavoidable evil, because it 
complicates the mechanism, and makes it 
more liable to disorders and failures of va- 
rious kinds, and lastly, because it takes away a 
part of the place which otherwise might 
have served to increase the breadth of the 
main-soring:. 

For these reasons it is no wonder that the 
question has been earnestly considered, 
whether it would be possible to dispense en- 
tirely with the stop-work, without compro- 
mising the solidity or the steady rate of a 
watch, and without exposing the main-spring 
to any disproportionate strain. This ques- 
tion requires a careful study, for the advan- 
tages to be obtained from the suppression of 
the stop-work are of considerable importance. 
Thus it will only be necessary to investigate 
whether these advantages are not outweighed 
by some grave inconveniences. 

47. The omission of the stop-work has 
been tried in a manifold way. It is more 
than twenty years since that a spring was 
employed for this purpose, to the outer end 
of which was riveted a piece of the same 
spring, of a length equal to about one-third 
of the inner diameter of the barrel. This 




piece was fixed backward in the direction of 
the spring, and its free end was resting 
against the hook in the barrel of the ordinary 
shape. This arrangement allows the spring 
to be coiled up to its outermost extremity, 
and the short piece riveted to it will then rest 
in an oblique direction against the hook, and 
prevent any fartl er winding. (Fig. 12.) 

Fig. 12. This system is su- 

perior to the simple 
omission of the stop- 
work, because it pre- 
serves the spring 
much more against 
breaking; but it does 
not protect the other parts of the movement 
from the sudden strains resulting from incon- 
siderate winding; a fault, though, which may 
be urged against any of the kinds of stop- 
work hitherto referred to. 

This arrangement looks rather primitive, 
but it ought not to be totally rejected. I was 
desirous of obtaining a correct idea of its 
merits, and constructed, about sixteen years 
ago, two small ladies' watches, which had to 
be very flat, with barrels of this kind. These 
watches have been kept in constant use by 
persons in my immediate neighborhood, and 
thus I have had them under constant obser- 
vation all this time ; they gave satisfaction as 
to the rate of going, and none of the springs 
have been broken at the present time. 

I recently saw some watches of American 
origin, the barrels of which were arranged 
in quite a similar way, with the only differ- 
ence that the piece riveted to the end of the 
spring had two pivots at its free end, the one 
of which moved in a hole through the bottom 
of the barrel, and the other in the same way 
was held in the barrel cover. 

48. Some years ago a system was invented 
by which the weak points of the one just 
mentioned are avoided, and the stop-work 
entirely dispensed with. These are the free 
springs of Mr. A. Philippe. An examination 
of their advantages, and of the objections 
raised against them, will not be out of place 
here. 

These free springs are made or arranged 
in such a way as to take their hold in the 
barrel without the usual hook, merely by the 
greater tension and strength of their outer 



AMERICAN HOROLOGICAL JOURNAL. 



199 



coil, which, for this purpose, is of about dou- 
ble the thickness of the acting part of the 
spr : ng. The relative thicknesses of these two 
parts must be kept in such proportion that 
the outer coil, always keeping a frictional hold 
in the barrel, follows the winding movement, 
but only when the spring has attained a cer- 
tain maximum of tension. Thus, any tension 
of the spring beyond this maximum is ren- 
dered impossible, if the winding is continued 
ever so long (Fig, 13). 

49. The springs 
of this kind have 
been, and may be 
executed, in two 
different ways. Ac- 
cording to the one, 
the thicker part is 
a part of the spring 
itself; while the 
other way consists 
in adding to a 
sj^ring of the usu- 
al kind a separate piece of greater strength, 
equalling in length the inner periphery of 
the barrel, and forming, as it were, an elastic 
bridle for the main-spring, which is attached 
to it by a hook (Fig. 14). The effect of the 
two dispositions, of course, is the same. 

Fto. 14. 





50. It is not easy to pronounce briefly an 
opinion for or against the free spring ; for, 
judging equitably its merits, we have to con- 
sider its drawbacks and the objections raised 
against it by watchmakers and repairers, and 
balance them against the advantages it pro- 
mises. These hitter are : 

1. Greater height of barrel, allowing to 



employ for a watch of the same size a broader 
and thinner main-spring, which is consequent- . 
ly less exposed to accidents, and gives a more 
uniform traction. 

2. Economy in the manufacturing of the 
barrel. This advantage is, however, in a de- 
gree absorbed by the higher price of the free 
spring, but this price will be considerably re- 
duced if the free spring should become a 
regular article of trade. 

3. Complete elimination of all derange- 
ments of the watch, resulting from defects or 
disorders of the stop-work. 

4. Protection of the movement against all 
injury arising from inconsiderate and rough 
winding. 

5. Lengthened period of daily march with 
once winding, because the free springs gene- 
rally are made so as to admit a tension of six 
turns or more. 

These advantages, especially those from 3 
to 5, are of great importance, and especially 
the one No. 4 has not yet been so much ap- 
preciated as it ought to be. 

51. The drawbacks of the free spring are 
the following : 

1. The absence of distinct perception, 
marking the end of the winding operation. 
This objection can be removed by cutting 
three or four vertical grooves into the inner 
cylindrical surface of the barrel, and by giv- 
ing the end of the spring a slight bend out- 
ward, so that it penetrates a little into one 
of these grooves. If the maximum of ten- 
sion of the spring is attained, the end of the 
spring will no more be arrested by the hold 
in the groove, and slips into the next one, 
thereby giving an easily audible click, which 
is a warning that the winding is completed. 
This sudden little motion is at the same 
time perceptible to the touch. 

2. The great inequality of traction, which 
must necessarily exist between the two ex- 
tremities of the development of the spring. 
This objection seems to be a serious one at 
first sight, because the watch, if not regular- 
ly wound, will continue to go till the tension 
of the spring is almost exhausted ; and it can- 
not be doubted that in the last hours of ex- 
piring march, the watch may show some al- 
teration of rate as compared with the rate it 
keeps when regularly wound. But every one 



200 



AMERICAN HOROLOG1CAL JOURNAL. 



'will admit that no watch can be expected to 
perform in an irreproachable way if it is sub- 
jected to such careless treatment ; besides, 
let me ask, what would be the consequences 
of a neglect in winding a watch provided 
with the stop-work ? It would lead to a to- 
tal stopping of the watch — a rather disagree- 
able occurrence, especially when travelling; 
and it is precisely under exceptional circum- 
stances that the winding is most likely to be 
forgotten. In such a case, the owner of a 
watch with the free spring would have to ac 
knowledge it as an advantage that his watch 
maintains its march, if even with a deviation 
of some minutes, which, however, would be 
hardly possible with a good watch, even 
under such uncommon circumstances. 
. 52. Thus, the two principal objections 
against the free spring are completely atten - 
uated. But there are several practical diffi- 
culties which make most watchmakers averse 
to its employment. This is chiefly the incon- 
venience of being obliged to keep an assort- 
ment of free springs, besides the stock of 
common springs for cases of breakage, and 
the higher price of the free springs adds to 
the weight of this argument. Spriogs of the 
common kind, on the contrary, are cheap and 
easy to procure. 

These circumstances made me reflect 
whether there was not some means of enjoy- 
ing the incontestable advantages of the free 
spring, without resigning the facility of re- 
placing a broken spring of the usual system. 
I think I have found out a remedy; at least 
one available in a case of need. I take a 
common spring of suitable breadth and thick- 
ness for the barrel, and I break off a piece of 
the outer end and corresponding in length 
with the interior periphery of the barrel. 
Out of the end of this piece I form a hook to 
which the spring is hooked in the common 
way, so that the detached piece extends 
backward in the direction of the length of the 
spring (Fig. 15). 

This arrangement has the effect that the 
pressure of this piece against the inside of 
the barrel increases with the tension of the 
spring, while with Philippe's arrangement, the 
traction of the spring diminishes the friction 
of the cuter turn; and this is the reason why 
this latter contrivance requires the detached 



pieces stronger than the spring itself. In the 
modification just mentioned, a piece of the 



Fig. 15. 




main spring itself is sufficient; and its resist- 
ance may be increased by the grooves in the 
barrel, and by a projection punched at the 
end of the piece, and lessened by shortening 
the same. I think a spring arranged in this 
way would soon make friends, because it 
offers all the advantages of the free spring, 
without its difficulties for the practical re- 
pairer. At any rate, it offers the means of 
providing a watch, in which a free spring is 
broken, with a new spring in suitable condi- 
tions, from the ordinary stock of springs on 
hand. 



COuRECTION. 

Editor Hobological Joubnal : 

Kindly permit me to correct the reading of 
my communication of December last. 

Page 127, Fig. 1 — n 1 A and n ! A should be 
joined by dotted lines, indicating the line of 
centres, viz : centre of formation and genera- 
ting circles. 

Then page 126, column the second, line 
third, it should read thus: ... .its radius 
forming, with the line of centre, the angles 
o n l A, o ri 1 A, o n % A. 

Also, page 128, column first, formula, fourth 
line, it should read thus: 

c = line of centres, 
that being the term employed. 
Yours, &c. 

J. Herrmann. 



AMEKICAN HOROLOGICAL JOURNAL. 



201 



HEAT. 



NUMBER SEVEN. 



HARDENING OF STEEL VARIOUS METHODS OF AP- 
PLYING THE HEAT VARIOUS METHODS OF COOL- 
ING PRECAUTIONS AGAINST CRACKING CAUSES 

OF STEEL BECOMING HARD STEEL LARGER WHEN 

HARD VARIOUS METHODS OF TEMPERING 

VARIOUS METHODS OF COLORING AND BLUING 

THE OIL BATH, SAND BATH, MERCURY BATH, ETC. 

"We have now to consider the important 
process of hardening steeL and the changes 
produced thereby. It is not requisite that 
the hardener should be a chemist, but some 
slight acquaintance with chemistry, or of the 
action of substances upon each other, will be 
extremely serviceable to him. To be un- 
qualified in this respect will be laboring in 
the dark; a successful result may often be 
obtained, but it will be very imperfectly 
known how it happened, and it will afford no 
valuable instruction for the future. There 
are too many who entertain the opinion that 
they have nothing to learn, and in effect say, 
that having served an apprenticeship to their 
business they know everything. These we 
do not attempt to convince, but the prudent 
artisan, whose first care is generally to pro- 
vide himself with tools adapted to his labors, 
we would ask to improve his knowledge of 
the nature of the materials from which they 
are made ; the proper choice and manage- 
ment of which constitutes the first step 
towards success in mechanical pursuits. 

The degree of heat necessary to harden 
steel differs with the different kinds. The 
best kinds only require a low red heat — the 
lowest heat necessary to effect the desired 
purpose being the most advantageous, and to 
impart to it an extra portion of heat must 
partly destroy its most valuable properties, 
and for this misfortune there is no remedy; 
for if cast steel is overheated it becomes 
brittle, and can never be restored to its origi- 
nal quality; therefore it will be quite incap- 
able of sustaining a cutting edge, but will 
chip or crumble away when applied to the 
work. There are various ways of applying 
heat to articles when they require to be hard- 
ened. The methods to be adopted will, of 
course, depend upon the shape and size of 
the articles, also upon the quantity required 



to be operated upon at the same time; for 
in some instances a large quantity can be 
heated and hardened as expeditiously as a 
single article. Sometimes it is requisite to 
heat the articles in the midst of the fuel of a 
hollow fire; at others it is necessary to heat 
them in an open fire; and sometimes it is 
desirable to enclose and surround them with 
carbon in a sheet-iron box, and heat the 
whole in a hollow fire, or a suitable furnace; 
and in some instances it is more convenient 
to heat them in red hot lead. A more uni- 
form degree of heat can be given to some 
articles by heating them in red hot lead than 
by any other means. A gas flame, or the flame 
of a candle, or a spirit lamp, is very conveni- 
ent for heating small articles, and some 
articles may be sufficiently heated by placing 
them between the red hot jaws of a pair of 
tongs. Sometimes it is necessary to insert a 
piece of iron pipe in the midst of the igni- 
ted fuel of the fire, and then place the articles 
in the pipe; clock pinions, and long, small 
arbors and broaches being generally hardened 
in this manner. All bright articles, which 
are made of steel, and require to be hardened, 
are the better for being heated previous to 
immersion in contact with carbon. To sup- 
ply carbon to the surface of steel articles, 
they may be enclosed in a sheet-iron box, 
and surrounded on all sides with either wood 
or animal charcoal; the whole will require 
to be placed in a furnace, or hollow fire, and 
heated to redness; but if the hardener be un- 
acquainted with the conducting power of the 
charcoal he will be apt to draw the box out 
of the fire too soon. To make sure, all the 
articles should be examined or tested in some 
way to see that they are at the proper heat 
before they are immersed in the water. 

It is obvious that the colder the water the 
more effectually it hardens the steel; and the 
more especially when the steel is immersed 
suddenly, and a rapid movement given to it 
whilst it is becoming cool; but when fresh 
cold water is used there is always great dan- 
ger of the steel cracking. The softer the 
water is, the less is the liability of the steel to 
crack; and water at a temperature of 60° is 
said to be the most favorable to hardening 
without the risk of cracking. When steel is 
required to be extremely hard, it may be 



202 



AMERICAN HOROLOGICAL JOURNAL. 



quenched in mercury; but it is obvious that 
this fluid can only be used on a small scale. 
Brinish liquids, or water charged with com- 
mon salt, produce rather more hardness 
than plain water. We remember a few years 
ago we had occasion to make a small drill 
very hard. It was in the hottest of the sum- 
mer months, and we quenched the drill in 
what we supposed to be a glass of water that 
was convenient. The drill proved to be much 
harder than when quenched in oil, as we had 
previously done, and bored through several 
pieces of thin hard steel without materially 
dulling the edge, and was the cause of much 
remark among those who witnessed the oper- 
ation. It turned ont, however, that what we 
supposed to be pure water was in reality lem- 
onade, which the workmen had been drink- 
ing, and to this cause we attributed the extra 
hardness of the drill. Ever since then lem- 
onade has been used for such purposes when 
it can conveniently be had, and that too 
with the very best results. All kinds of 
small springs may be advantageously hard- 
ened in oil, or pure soft water, with a small 
quantity of oil floating on the top. Oil or 
tallow appears to give a certain amount of 
toughness to steel in hardening which is not 
attained by any other method or liquid. 

It may not be generally known that the 
hardening of steel does not necessarily de- 
pend on the immersion of the metal in a 
liquid of any kind, but may be effected 
equally as well by the application of cold; 
as, for instance, watchmakers harden very 
small drills by suddenly drawing them 
through the air after being heated ; or when 
we leave a thin piece of red-hot steel between 
a large hammer and the face of an anvil, the 
steel becomes as hard as when quenched in a 
liquid. Before putting any article in the fire 
to heat, before hardening, it is necessary to 
examine the shape in order to know which 
way it will require to be immersed in the 
water so as to lessen the risk of its cracking or 
bending; every kind of article requiring to be 
dipped in a particular way, according to its 
shape. For instance, if there be a stout part 
and a thin part in the article, the stoutest 
part should always enter the water first, as it 
causes the steel to cool more uniformly, and 
lessens the risk of fracture; because if the 



thinnest part of the article be allowed to en- 
ter first it will become cool much sooner than 
the stout part; and the stout part contracts, 
by the loss of heat, after the thin part is 
fixed; the thin part, in its then hard and 
brittle state, cannot give, consequently it 
breaks; or, if it does not break at the time of 
hardening, it is held in such a state of ten- 
sion or strain that it is ready to break when 
applied to the work. 

Drills and all kinds of tools and work that 
are only hardened at the ends, and which are 
only partially dipped into the water, should 
never be held still when they are becoming 
cold; but should, after they are dipped to 
the required depth, have a sudden vertical or 
other movement given to them. When the 
water cools them across in a straight line, it 
causes the hardened'part to have a tendency 
to tear from the soft part; but whether the 
steel breaks asunder or not, or whether there 
are signs of fracture or not, this tearing of 
the particles from each other when the hard- 
ening terminates in'a strict line, must always, 
with highly carbonized steel, more or less 
take place, when it is known that hardened 
steel occupies more space than soft steel, and 
that the density of the steel is different in the 
two states. It is pretty generally known to 
those who are much employed in the process 
of hardening steel, and to those in the habit 
of fitting up various kinds of steel work re- 
quiring great nicety, that the hardening of 
steel often increases its dimensions; so much 
so, that pieces of work fitted in a soft state 
will not fit when hardened, and the workman 
has to resort to the process of grinding to 
make the work fit. Some explanation of this 
phenomenon is given in No. 4 of these arti- 
cles, under the head of permanent elongation 
of metals, and change of the zero point in 
thermometers. 

Many theories upon the cause of steel be- 
coming hard by the process of heating and 
suddenly cooling it, have been formed. It is 
believed by some that the hardness of steel is 
caused by the compression of the whole of 
the particles into a denser state; and in con- 
firmation of this, they say that steel always 
looks closer and finer in the grain after being 
hardened. Now, if this was the only cause of 
steel becoming hard, how is it that the steel 



AMERICAN HOROLOGICAL JOURNAL. 



203 



gets larger in dimensions ? It is quite reason- 
able to suppose, if the particles of the hard- 
ened parts of the steel are removed to a 
greater distance from each other, that the 
steel would look considerabley more open and 
coarser in the grain; and consequently it may 
be inquired if it is not the compression of the 
whole of the particles into a denser state that 
is the cause of steel looking closer in its tex- 
ture after hardening. The answer is, if we 
accept the theory that it is the crystallization 
of the carbon which causes the hardness in 
the steel, that the carbon expands in the act 
of crystallization in a similar manner that 
water expands by extreme cold in crystalliz- 
ing into ice, and fills up every pore or crev- 
ice, and gives the steel the appearance of be- 
ing closer and more solid. 

Such is a slight sketch of the causes that 
lead to the hardening of steel, and although 
much more might be said, we do not think it 
to be necessary to entangle the reader with a 
lot of theories on the subject, although it may 
be necessary for his amusement, and for the 
exercise of sound judgment, to occasionally 
glance at them in treating fully the purely 
mechanical operations. 

The tempering of steel, after being hard- 
ened, is also of the greatest importance. 
Large articles are usually tempered by apply- 
ing heat to them till their surfaces present a 
certain color, according to the degree of 
hardness required; but when a large number 
of small articles are required to be tempered, 
it will be too slow a process to temper them 
by color, and a more expeditious method 
must be adopted. A very convenient way of 
uniformly heating a large quantity of small 
articles at once, no matter how irregular 
their shape, providing the heat is not applied 
too suddenly, is to put them into a suitable 
iron or copper vessel, with as much tallow or 
cold oil as will just cover them, and then to 
place the whole over a small fire, and slowly 
heat the oil until a sufficient heat is given to 
the articles for the temper required. 

It may perhaps be well to remind the 
young beginner that the temperature of the 
oil may be raised to 600° of heat, or rather 
more, and consequently any temperature be- 
low a red heat may be given to the articles 
by the heated oil. Certain degrees of tem- 



perature may be estimated by the following 
circumstances: When the oil is observed to 
smoke, it indicates the same temperature as 
a straw color, and if measured by a thermom- 
eter, will be about 450°. When the smoke be- 
comes more abundant, and of a darker color, 
it indicates a temper equal to a brown, and 
the oil will measure 500° by the thermometer. 
If the heat be continued so that the oil will 
yield a black smoke, and still more abundant, 
this will denote a purple temper, and the oil 
will contain about 530° of heat. The next 
degree of heat may be known by the oil tak- 
ing fire, if a piece of lighted paper be pre- 
sented to it, but yet not so hot as to burn 
when the lighted paper is withdrawn. The 
temperature of the oil at this stage will be 
about 580°. The next degree of heat may be 
known by the oil taking fire and continuing 
to burn. This is the temper best suited for 
most kinds of springs,' and is the temper clock- 
makers use mostly for pinions and arbors. 
Any single article, to save trouble of heating 
in a vessel, may be smeared over with oil and 
held over a clear fire, or over a piece of hot 
iron, or a candle, or flame of almost any kind, 
when there is no smoke. It formerly was a 
common, and also a very good custom, to 
harden small drills and taps in the flame of a 
candle with a blow pipe, quench them in the 
grease of the candle, and burn off the grease 
till the desired temper was attained. 

Although the above method is a reliable 
process for tempering steel articles equally 
throughout, however irregular may be their 
shape, still it is often required, in fine work, 
to temper the articles so as to leave the color 
visible and regular on the surface ; and also it 
is often required to give soft articles a blue or 
other color by way of ornament. Certain 
articles can thus be colored by skilfully hold- 
ing them over a hot iron, or spirit lamp; but 
when the articles are of irregular shape, it 
becomes very difficult to impart a regular 
color to them in this manner. The sand bath 
is frequently used for this purpose, and, in 
the hands of skilful operators, good results 
are obtained; but a neater and more reliable 
method has been introduced, and which we 
have ourselves used with great success; and 
we recommend it to all who require to blue 
irregular-shaped pieces of work. 



204 



AMERICAN HOROLOGICAL JOURNAL. 



The following experiment is simple, and 
clearly exhibits and illustrates this manner of 
tempering : Let a plate of steel, finely 
polished, be so laid as to float on the surface 
of a bath of mercury, in which plunge the 
bulb of a thermometer 600° Fahr. No 
change of color will be visible on the steel 
until the mercury has risen to 430°, and then 
it will be so faint as only to be perceptible by 
comparison with a plate that has not been 
heated. At 450° the color will be a fine pale 
straw, which, as the heat increases, will be- 
come deeper, and successive changes will 
take place until it be heated up to the boil- 
ing point of mercury, which degree of heat 
can be attained with a good argand gas 
burner. 

Such is a review of the effects of heat in 
hardening and softening metals. Further 
practical directions might easily be multi- 
plied, but the necessity for much further 
minuteness of detail upon most of the pro- 
cesses will be removed by a little observation, 
experience, and perseverance, which we wish 
all our young friends to cultivate. Those 
who postpone perseverance by satisfying 
themselves with the hope that length of prac- 
tice will perfect them, will in the end regret 
their delusion, and may ineffectually try to 
recover their loss, when habitual languor, and 
other injurious habits, have rendered the 
mind averse to observe, and the hand unable 
to perform. 



-o- 



BKASS ALLOYS. 



"We shall continue the subject of metals in 
the condition of alloys, somewhat in the order 
at their importance in our art. 

Brass being more largely demanded in our 
e >nstructions will claim the first consideration. 
So metal, either simple or compound, iron 
excepted, enters so largely into mechanical 
c >nstruction as brass. Scarcely any machine, 
large or small, is completed without some 
demand being made on this useful alloy of 
copper and zinc. 

Copper, one of its constituents, was known 
to the ancients, and derived its name from 
the island of Cyprus, where it was first 
wrought by the Greeks. Before the discovery. 



of malleable iron it was the chief ingredient 
in the manufacture of domestic utensils and 
instruments of war. Copper is largely met 
with in the metallic state, but still more 
largely in combination with the metalloids, 
oxygen, sulphur, and arsenic. The sulphurets 
are the chief source of supply for commer- 
cial demands. Copper is very malleable and 
ductile, and may be drawn into fine wire or 
beaten in thin leaves — its tenacity being only 
inferior to iron. It has a peculiar taste, and 
by friction evolves an odor peculiar to itself 
and somewhat disagreeable ; at a white heat 
it passes off in vapor, which, in the open* air, 
burns with a green flame. At ordinary tem- 
peratures this metal does not oxidize in dry 
air, but quickly changes in moist air; it then 
becoming covered with a strong adherent 
coat of carbonate of copper. Heated to red- 
ness in the air, copper becomes oxidized — a 
black scale covering its surface. Dilute sul- 
phuric or muriatic acid scarcely acts upon it, 
but dilute nitric acid dissolves it readily. 
Sulphate of copper, or " blue vitriol," is the 
most important salt of copper ; it occurs in 
large blue crystals, which are soluble in four 
parts cold or two of boiling water. This salt 
is the source of several blue and green colors 
used by dyers and calico printers, and in some 
kinds of writing ink. Ink of this character 
has the inconvenience that in writing with 
steel pens metallic copper is precipitated on 
the steel, and clogs the pen. This salt is also 
a powerful preservator of animal substances, 
which when imbued with it and dried become 
unaltered. 

Zinc, the other constituent of brass, is first 
mentioned as a distinct metal by Paracelsus, 
but it appears to have been known in China 
and in India from an early period. It has a 
bluish, white color, and its recent fracture 
presents a brilliant crystalline surface. It is 
somewhat brittle at ordinary temperatures, 
but when heated to between 212° and 300° it 
becomes malleable and ductile, and may be 
rolled or hammered out without fracture, and 
what is remarkable, retains its malleability 
when cold. The sheet-zinc of commerce is 
made in this way. If the heat be increased 
to about 450° the metal again becomes brit- 
tle, and may be reduced to powder. At a 
bright red heat zinc boils and volatilizes, and 



AMERICAN HOKOLOGICAL JOURNAL. 



205 



if air be admitted burns -with a vivid, whitish 
blue light, generating the oxide, a white, 
flocculent matter, called flour of zinc, or phil- 
osopher's wool. 

Chloride of zinc combines with sal-ammo- 
niac to form double salts. Zinc dissolved in 
hydrochloric acid, with an equivalent of sal- 
ammoniac added, is Tiseful in tinning and soft- 
soldering copper, iron, etc. 

The term brass is usually applied to the 
yellow alloy of copper with about half its 
weight of zinc, commonly called yellow brass ; 
but copper with about one-ninth its weight of 
tin is the brass of which ordnance are cast, 
called gun metal ; and similar alloys used for 
the brasses or bearings of machinery are cal- 
led hard brass, and when employed for statues, 
medals, and articles of virtu, are called 
bronzes. We shall confine ourselves, in this 
article, to the alloy of copper and zinc only; 
the harder alloys being almost entirely foreign 
to our trade. In the language of the foundry, 
a pound of copper is taken as the standard 
in speaking of proportions. Yellow brass, 
they will tell you, is 6 to 8 oz. of zinc ; mean- 
ing 6 to 8 oz. of zinc to the pound of copper. 
In the following list of alloys the numbers at 
the beginning of each paragraph denote the 
ounces of zinc to every pound of copper. 

| to \ oz. is added to copper which is to be 
cast, for in its pure state it is difficult to get 
pure copper to make sound castings. The 
compound is frequently made by adding 4 oz. 
of brass to every 2 cr 3 pounds of copper. 

1 to \\ oz. forms gilding metal for common 
jewelry. The common formula is 4 parts 
copper to one of calamine brass, or 1 lb. cop- 
per with 6 oz. brass. 

3 oz. — Red sheet brass, or 5| copper and 1 
zinc. 

3 to 4 oz. — Bath metal, pinchbeck, Maun- 
heim gold, oroide, or whatever else for a 
name the gullible public will swallow. It 
resembles inferior jeweller's gold alloyed with 
copper; some contains a little tin. 

6 oz. — This brass will bear soldering. 
Bristol brass is said to be of this proportion. 

8 oz. — Ordinary brass; less adapted to 
soldering than 6 oz., as it is more fusible. 
This is a brass patented in 1781 by Emerson. 
It is the common ingot brass, made by simple 
fusion of the two metals. 



9 oz. — This is one of the extremes of 
i Muntz's patent sheathing. 

10§ oz. — Is Muntz's metal; or 40 zinc, 60 
' copper. The patentee's statement is that any 
proportion between the extremes of 50 zinc 
and 50 copper, and 37 zinc and 63 copper, 
will roll and work at the red heat, but 40 to 
60 is preferred. The metal is cast into ingots, 
heated to a red heat, into ship's bolts and 
other fastenings, rolled into sheathing, etc. 

12 oz. — Spelter solder for copper and iron 
is sometimes made in this proportion; for 
brass work the metals are usually mixed in 
equal parts. 

12 oz. — Pale yellow, suitable for dipping in 
acids. 

16 oz. — Soft spelter solder, fit for ordinary 
brass work. About 14 lbs. of each are melted 
together and poured into an ingot mould with 
cross ribs, which indent it into squares of 
about 2 lbs. weight. Much of the zinc is lost 
in fusing and casting, so that the ultimate 
proportion is less than 16 oz. 

The lumps are afterwards heated nearly to 
redness on a charcoal fire, and are quickly 
broken up in an iron mortar. If the heat be 
too great, the solder forms into a cake, or 
coarse lumps, and becomes tarnished. At a 
proper heat it becomes nearly granulated ; 
is passed through a sieve and remains a 
bright yellow color ; 16| oz. is Hamilton's and 
Parker's mosaic gold, which is dark colored 
when first cast, but after dipping assumes a 
beautiful golden tint ; when cooled and brok- 
en, the yellowness disappears. The best pro- 
portions are about 16J to 17 oz. to the pound. 

32 oz., or 2 zinc to 1 copper. —A bluish white 
brittle alloy, so crystalline that it may be 
pounded cold in a mortar. 

128 oz., or 2 oz. copper to every pound of 
zinc. — A hard crystalline metal, differing but 
little from zinc, but more tenacious. It is 
sometimes used for polishing taps. 

The alloys from 8 to 16 oz. are extensively 
used for dipping, as in the various brass ar- 
ticles used for furniture; the metal being first 
annealed before it is scoured or cleaned, or 
the acids, lacquers, or bronzes applied. The 
ordinary range of good yellow brass, that 
files and turns well, is from 4| to 9 oz ; with 
additional zinc it becomes harder and more 
crystalline, and with less, more tenacious. Up 



206 



AMERICAN HOROLOGICAL JOURNAL. 



to 8 or 10 oz. the alloys maintain their mal- 
leability and ductility. The red color of cop- 
per merges into that of yellow brass at 4 to 
5 oz., and remains but little altered up to 8 
or 10 oz ; after this it becomes whiter. 

Owing to the very volatile and inflammable 
nature of zinc in the furnace, these propor- 
tions must not be strictly taken, for whatever 
weight of the two constituents be put in the 
crucible there will always be a rapid, and, to 
a certain extent, uncontrollable waste of zinc. 

The native ore (carbonate) of zinc, called 
Calamine is not infrequently used for the 
manufacture of glass. For this purpose the 
native Calamine is broken and ground in a 
mill; after being calcined, the galena (lead 
ore) contained in it is separated by washing; 
it is then mixed with about \ part of char- 
coal, the mixture put into large cylindrical 
crucibles, with alternate layers of copper, cut 
in small pieces, or in the form of shot ; pow- 
dered charcoal is then covered over the 
whole, and a cover luted on, and placed in 
the furnace — the zinc of the carbonate unit- 
ing with the copper, without assuming, ap- 
parently, the metallic form. We are largely 
indebted to Mr. Holtzapffel in his work on 
" Mechanical Manipulations" for the details of 
a number of interesting experiments for the 
best methods of forming alloys of copper and 
zinc. " The zinc was added to the copper in 
various ways ; namely in solid lumps, thin 
sheets hammered into balls, poured in when 
melted in an iron ladle, and all these both 
while the crucible was in the fire and after 
its removal from the same. The surface of 
the copper was in some cases covered with 
broken glass, or charcoal, and in others 
uncovered, but all to no purpose ; as from \ 
to i the zinc was consumed with most vexa- 
tious brilliancy, according to the modes of 
treatment ; and these methods were therefore 
abandoned as hopeless. I was the more 
diverted from the above attempts, from the 
well-known fact that the greatest loss always 
occurs in the first mixing of the two metals, 
and which the founder in general is anxious 
to avoid. Thus, when a very small quantity 
of zinc is required, as for so-called copper 
castings, about 1 oz. of brass are added to 
every 2 or 3 lbs. of copper. And in ordinary 
work a pot of brass, weighing 40 lbs., is made 



up of 10, 20, or 30 lbs. of old brass, and § pi 
the remainder of copper. These are first 
melted. A short time before pouring, the ^ 
of the new metal, or zinc, is plunged in when 
the temperature of the mass is such that it 
just avoids sticking to the iron rod with which 
it is stirred." In forming an alloy of 2.75 
copper with 1 zinc, the proportions of which 
require to be very carefully preserved, that 
alloy was found to expand equally with the 
speculum metal to which it had to be soldered. 
Lord Rosse found that by employing a furnace . 
deeper than usual, and covering the metal with 
a layer of charcoal powder 2 inches thick, 
the loss was reduced to the minimum, and 
almost exactly the 180th each casting. 

Yellow brass may, by rolling, have imparted 
to it a good degree of elasticity, and has, to 
some small extent, been used for the springs 
of clocks; such springs after a time lose their 
elasticity and remain coiled. This is prob- 
ably owing to the fact, that the zinc, which is 
a component part of the brass, has a perpet- 
ual inclination to assume its normal crystal- 
line condition, and this tendency undoubtedly 
is the cause of the " rotting " of brass when 
exposed to acid fumes, or even a damp 
atmosphere for a considerable time. When 
kept perfectly dry, or protected by a coat of 
gilding, the fibrous condition imparted to 
cast brass by rolling, drawing, or hammering, 
undergoes no perceptible change. For almost 
every purpose in our art, brass is required to 
be quite hard, which hardness is best impart- 
ed to it by hammering. In rolled brass the 
particles seem to elude compression, in some 
considerable degree, by flowing in front of 
the pressure rollers, in the same manner that 
water is forced out of the fabric by a clothes- 
wringer — the metal being more elongated 
than compressed. 

On the contrary, in hammering, the metal 
seems to be driven down upon itself, compres- 
sing and hardening the part directly beneath 
the hammer; the repetition of the strokes 
forcing the hardened particles downward into 
the softer metal below, and so on till the 
whole mass may be very closely driven to- 
gether without very much enlarging its area; 
slight, oft-repeated strokes, with a planishing 
(flat-faced) hammer, will best produce the 
maximum hardness. 



AMERICAN HOROLOGICAL JOURNAL. 



207 



LIGHT. 



NUMBER FOUR. 



Upon the refraction of light is based the 
whole science of optics, and the construction 
of lenses. A lens is a portion of a refracting 
substance which is bounded by curved sur- 
faces ; if the surface be spherical the lens is 
called a spherical lens. Lenses are divided 
into two classes, one of which renders parallel 
rays convergent, the other of which renders 
such rays divergent. Each class comprises 
three kinds of lenses, which are named as 
follows : 

CONVERGING LENSES. 

1. Double convex, with both surfaces con- 
vex. 

2. Plano-convex, with one surface plane, 
the other convex. 

3. Concavo-convex (meniscus), with aeon- 
cave and convex surface, the convex being 
the most strongly curved. 

DIVERGING LENSES. 

1. Double concave, with both surfaces 
concave. 

2. Plano-concave, with one surface plane, 
the other concave. 

3. Convexo-concave, with a convex and 
concave surface, the concave surface being 
the most strongly curved. 

A straight line drawn through the centre 
of the lines, and perpendicular to its two sur- 
faces is the principal axis of the lens. A lu- 
minous beam falling on a convex lens, parallel 
to the axis, has its constituent rays brought 
to intersection at a point in the axis behind 
the lens. This point is the principal focus of 
the lens, and this principal focus is the focus 
of parallel rays. 

If a luminous point be placed in the focus 
of a convex lens, the rays from it will pass out 
on the opposite side as parallel rays. If the 
luminous point approach the lens, the rays 
will pass out on the opposite side, till diver- 
gent. Producing them backward they 
will intersect on that side of the lens on which 
stands the luminous point. The focus here 
is virtual. A body of sensible magnitude 
placed between the focus and the lens would 
have a virtual image. "When an obj ct of 
sensible dimensions is placed anywhere be- 



yond the principal focus, a real image of the 
object will be formed in the air behind the 
lens. The image may be either greater or less 
than the object in size, but the image will 
always be inverted. The position of the image 
and the object are, as before, convertible. In 
the case of concave lenses the images are 
always virtual. 

A spherical lens is incompetent to bring all 
the rays that fall upon it to the same focus. 
The rays that pass through the lens near its 
circumference are more refracted than those 
which pass through the central portions, and 
they intersect earlier. Where perfect defini- 
tion is required it is therefore usual, though 
at the expense of illumination, to make use of 
the central rays only. This difference of focal 
distance between the central and circumfer- 
ential rays, is called the spherical aberration 
of the lens. A lens so curved as to bring all 
the rays to the same focus — is called aplanatic; 
a spherical lens cannot be rendered aplanatic. 
As in the case of spherical mirrors, spherical 
lenses have their caustic curves (diacaustics) 
formed by the intersection of the refracted 
rays. 

VISION AND THE EYE. 

The eye is a compound lens, consisting of 
three principal parts: the aqueous humor, the 
crystalline lens, and the vitreous humor. The 
aqueous humor is held in front of the eye by 
the cornea, a transparent horny capsule, re- 
sembling a watch-glass in shape. Behind 
the aqueous humor, and immediately in front 
of the crystalline lens, is the iris, which sur- 
rounds the pupil; then follows the lens and 
the vitreous humor, which last constitutes 
the main body of the eye. The average diam- 
eter of the human eye is 10.9 lines.* Where 
the optic nerve enters the eye from behind, 
it divides into a series of filaments, which 
are woven together to form the retina, a deli- 
cate net- work of nerve tissue spread as a 
screen at the back of the eye. The retina 
rests upon a black, pigment, which reduces 
to a minimum all internal reflection. By 
means of the iris the size of the pupil may be 
made to vary within certain limits. When 
the light is feeble the pupil expands, when it 
is intense the pupil contracts; thus the 

• A lino is one-twelfth of an inch. 



208 



AMEBICAN HOKOLOGICAL JOUKNAL. 



quantity of light admitted to the eye is, to 
some extent regulated, the pupil also diminish- 
es slightly when the eye is fixed upon a near 
object, and expands when fixed upon a dis- 
tant one. The pupil appears black, partly 
because of the internal coating, but mainly 
for another reason. Could we illuminate the 
retina, and see at the same time the illumi- 
nated spot, the pupil would appear bright; 
but the principle of reversibility, so often 
spoke of here, comes into play; the light of 
the illuminated spot in returning outward re- 
traces its steps and finally falls upon the 
source of illumination. Hence to receive the 
returning rays, the observer's eye ought to be 
placed between the source and the retina; but 
in this position it would cut off the illumina- 
tion. If the light be thrown into the eye by 
a mirror pierced with a small oi'ifice, or with 
a small portion of the silvering removed, then 
the eye of the observer placed behind the 
mirror, and looking through the orifice, may 
see the illuminated retina. The pupil under 
these circumstances glows like a live coal. 
This is the principle of the ophthalmoscope, an 
instrument by which the interior of the eye 
may be examined, and its condition in health 
or disease noted. In the case of albinos, or 
of white rabbits, the black pigment is absent 
and the pupil is seen red, by the light 
which passes through the sclerotica, or white 
of the eye; when this light is cutoff the pupil 
appears black. In some animals, in place of 
the black pigment, is a reflecting membrane, 
the tapelum. It is the light reflected by the 
tapetum which causes a cat's eye to shine in 
partial darkness. The light in this case is 
not internal, for if the darkness be total the 
cat's eye will not shine. The photographer's 
camera is but an enlarged eye, the ground 
glass upon which the inverted image is re- 
ceived taking the place of the retina in that 
organ. For perfectly distinct vision it is 
necessary that the image upon the retina 
should be perfectly defined; in other words, 
that the rays from every point of the object 
looked at should converge to a point on the 
retina. 

THE PUNOTUM CAECUM. 

The spot where the optic nerve enters the 
eye, and from which it ramifies to form the 
net-work of the retina, is insensible to the ac- 



tion of light. An object whose image falls 
upon that spot is not seen. The image of the 
moon, a clock dial, or a human face, may be 
caused to fall upon this "blind spot," in 
which case the object is not visible. This 
can be illustrated by laying two white wafers 
on black paper, or two black ones on white 
paper, with an interval of 3 inches between 
them. Bring the right eye at a height of 10 
or 1 1 inches exactly over the left hand wafer, 
so that the line joining the two eyes shall be 
parallel to the line joining the two wafers. 
Closing the left eye, and looking steadily with 
the right at the left-hand wafer, the right- 
hand one ceases to be visible. In this posi- 
tion, the image falls upon the " blind spot " 
of the right eye. If the eye be turned in the 
least degree to the right or left, or if the dis- 
tance between it and the paper be augmented 
or diminished, the wafer is immediately seen. 
Preserving these proportions as to size and 
distance, objects of far greater dimensions 
than the wafer may have their images thrown 
upon the blind spot and be obliterated. The eye 
is by no means a perfect optical instrument. 
It suffers from spherical observation; a scat- 
tered luminosity, more or less strong, always 
surrounding the defined images of luminous 
objects upon the retina. By this luminosity 
the image of the ooject is sensibly increased 
in size; but with ordinary illumination the 
scattered light is too feeble to be noticed. 
When, however, bodies are intensely illumi- 
nated, more especially when the bodies are 
small, so that a slight extension of their 
images upon the retina becomes noticeable, 
such bodies appear larger than they really 
are. Thus the crescent moon seems to belong 
to a larger sphere than the dimmer map of 
the satellite which it seems to clasp. This 
augmentation of the true size of the optical 
image is called irradiation. Almost every 
eye contains bodies, more or less opaque, 
distributed through its humors. The so- 
called muscos volitantes are of this character; 
so are the black dots, snake-like lines, 
beads, and rings, which are strikingly visible 
in many eyes. Were the area of the pupil 
contracted to a point, such bodies might pro- 
duce considerable annoyance; but because of 
the width of the pupil, the shadows which 
these small bodies would otherwise cast upon 



AMERICAN HOKOLOGICAL JOURNAL. 



209 



the retina are practically obliterated, except 
■when they are very near the back of the eye. 

It is only necessary to look at the firma- 
ment through a pin-hole to give these shad- 
ows greater definition on the retina. 

If the letters of a book, held at some dis- 
tance from the eye, be looked at through a 
gauze veil placed near the eye, it will be 
found that when the letters are seen dis- 
tinctly the veil is seen indistinctly; conversely, 
if the veil is seen distinctly, the letters will 
be dimly seen. This demonstrates that the 
images of objects, at different distances from 
the eye. cannot be defined at the same time 
upon the retina. "Were the eye a rigid mass, 
like a glass lens, incapable of change of form, 
distinct vision would only be possible at one 
particular distance. We know, however, that 
the eye does possess a power of adjustment 
for different distances. This adjustment is 
effected, not by pushing the front of the eye 
backward or forward, but by changing the 
curvature of the crystalline lens. The image 
of a candle reflected from the front or rear 
surface of this lens, is seen to diminish when 
the eye changes as from distant to near 
vision, thus proving the curvature of the lens 
to be greater for near than for distant vision. 
The pi incipul refraction endured by the rays 
of light iu passing through the eye occurs at 
the surface of the cornea when the passage 
is from air to a much denser medium. The 
refraction at the cornea alone would cause 
the rays to intersect at a point nearly half an 
inch behind the retina. The convergence is 
augmented by the crystalline lens, which 
brings the point of intersection forward to 
the retina itself. A line drawn through the 
centre of the cornea, and the centre of the 
whole eye to the retina, is called the axis of 
the eye. The length of the axis, even in 
youth, is sometimes too small; in other words, 
the retina is too near the cornea, so that the 
refracting part of the organ is unable to con- 
verge the rays to a point upon the retina. In 
old age also the refracting surfaces of the eye 
are .slightly flattened, and thus rendered in- 
competent to refract the rays sufficiently. In 
both cases the images would be formed be- 
hind the retina, instead of upon it, and hence 
the vision is indistinct. A slight defect of 
this kind is remedied by holding the object 



at a distance from the eye, so as to lessen the 
divergence of the rays. When this defect is 
considerable, a convex lens placed in front of 
the eye helps to produce the necessary con- 
vergence. This is the use of spectacles. 

The axis of the eye is sometimes too long, 
or the curvature of the refracting surfaces 
may be too great; in either case, the rays 
entering the pupil are converged so as to 
intersect before reaching the retina. This 
defect is remedied by holding the object very 
near the eye so as to increase the divergence 
of the rays, or by interposing before the eye 
a concave lens, which produces the necessary 
divergence, thus throwing back the point of 
intersection to the retina. The eye is not 
adjusted at the same time for equally distant 
horizontal and vertical objects. The distance 
of distinct vision is greater for horizontal 
lines than for vertical ones. Draw with ink 
two lines at right angles to each other, one 
vertical and one horizontal; one of them is 
seen distinctly black and sharp, the other ap- 
pears indistinctly, as if drawn with lighter 
ink. Adjust the eye for the latter line, and the 
former will then appear indistinct. This dif- 
ference in the curvature of the eye in two 
directions may sometimes become so great as 
to render the application of cylindrical lenses 
necessary for its correction. 

These, and other imperfections of the eye, 
make the subject of the selection of spectacles 
a matter of no small moment. Wells, in his 
treatise on this subject, says : " I have no 
hesitation in saying, that the empirical, hap- 
hazard plan of selection generally employed 
by opticians, is too frequently attended by the 
worst consequences; and that eyes are often 
permanently injured, which might, by skilful 
treatment, have been preserved for years. 
For this reason I must strongly urge upon 
medical men the necessity, not only of exam- 
ining the state of the eyes, and ascertaining 
the nature of the affection, but of going even 
a step farther than this, and determining with 
accuracy the number of the*required lens. 
For this purpose they must possess a case of 
trial glasses, containing a complete assortment 
of concave, convex, and cylindrical lenses, 
glasses of corresponding number being kept 
by the optician, and give the patient a pre- 
scription for spectacles. By doing so the 



210 



AMEKICAN HOKOLOGICAL JOTJBNAL. 



patient is assured of being furnished with 
suitable and proper glasses," 

MANUFACTURE OF LENSES. 

The almost universal necessity for spectacle 
lenses, of every variety of curvature suited to 
the endless diversity of defects to which the 
eye is subject, opens a large field to cominer- 
cial enterprise. Probably no form of lens 
comes into more general use than those par- 
ticularly designed for spectacles, and the im- 
mense quantities used would astonish those 
not somewhat familiar with the business. 
Almost the whole supply was derived from 
Europe until recently, none being manufac- 
tured here, except a few of the finer kinds, 
for astronomical and optical instruments. 
These, commanding almost any price, could 
be profitably made by hand labor; but the 
smaller aud cheap spectacle eyes were obliged 
to wait for the advent of machinery. We 
know of no lenses manufactured by machin- 
ery in this country except at the establish- 
ment of Messrs. Surdam & White, Harlem 
Building, New York. English or French 
plate-glass, entirely free from tint of blue, 
green, or yellow, when viewed through its 
edge, is used for these lenses, first being 
broken up into small squares of a size suitable 
for the e} r es of spectacles. The first rough 
grinding is done in cast-iron forms, or 
basins, varying in size according to the focus 
desired. Shallow concave disks, of 20 inches 
diameter, are used for the lenses of long 
focus, and diminishing in size and increasing 
in depth, as the focus is to be shorter; the 
smallest, of perhaps 6 inches diameter, being 
used for a focus of 2 or 3 inches. Fitting into 
these concaves are segments of iron spheres 
of curvature exactly corresponding. These 
segments are given a peculiar circular and 
horizontal motion by an eccentric finger 
attached to a vertical rotating spindle placed 
over each of these grinding mills, and actuated 
by a band and pulley from a common 
shaft. 

The convex surface of this cast-iron grinder 
is then thickly coated with soft pitch, into 
which are pressed as many of the little squares 
of glass as will cover its whole surface, and is 
then inverted into its cast-iron concave, 
whi e the pitch is yet soft and yielding — the 
whole mass taking: the exact curvature of the 



matrix. When the pitch becomes hard 
the eccentric finger is attached, the band 
slips on the pulley, and the mass commences 
its eccentric revolutions. Emery and water 
are then supplied, and the process of grind- 
ing goes on till the glass squares are all 
ground to the dead surface ; the coarser 
emery is then washed out, and a finer grade 
supplied and the grinding goes on ; again 
they are washed carefully, and an impalpable 
flower of emery applied. By this time, the 
surfaces become semi-polished, but the final 
exquisite gloss must still be given, which is 
done by substituting for the iron concave, one 
of felt, and supplying rouge and water instead 
of emery. 

Some fifty of these grinding and polish- 
ing mills, arranged in suitable frames, and 
when all are busily in motion, look wonder- 
fully industrious and business-like. This 
process finishes, as you will notice, only one 
side of the lens; tbe pitch is then softened, 
the half finished lenses turned over, the pol- 
ished side imbedded in the pitch, and the 
second surface undergoes the same process ; 
this is the construction of the convex lenses. 
Concave lenses are ground by fixing the 
pieces of glass to the concave bed, and the 
moving convex disk does the grinding and 
polishing. The same process is used in 
grinding the lenses for stereoscopic instru- 
ments, only larger squares of glass are used. 
Great care and experience are necessary in 
washing and grading the grinding emery, 
and also in preparing the rouge for the 
final polish. "Brazilian pebbles," "Califor- 
nia diamonds," and all the various pebbles, 
of whatever name, undergo the same pro- 
cess, first being sawed in slips of the proper 
thickness ; of the long focus, eight or ten 
dozen are ground at once, but of 
the short focus — cataract glasses — no more 
than four or six can be done at one 
time. All the various forms of lenses — men- 
iscus, plano-convex, concavo-convex (peri- 
scopic) and concave — are made by varying the 
forms of the iron mills. 



We will pay fifty cents each for copies 
of Nos. 4 and 5, Vol. I., of the Horological 
Journal. 



AMEEICAN HOROLOGICAL JOURNAL. 



211 



HIM'S TO KEPALREltS. 



NUMBER TWO. 



Balance pivots, and other pivots running 
on cap jewels, can be made much thinner and 
yet much stronger than ordinary pivots, by 
making them conical. Not only are conical 
pivots stronger, but are also more elegant in 
appearance than straight pivots. To make 
conical pivots the repairer must provide him- 
self with some pivot files and a pivot rest for 
his lathe ; these extras he must construct 
himself (they not being sold in tool-sbops), 
in the following manner. The pivot files 
being the first consideration, the repairer 
must provide himself with three pieces of 
long and flat steel, or three old pivot files ; 
one for filing, one for grinding, and one for 
polishing the pivot. The first-named file is 
first heated to a cherry red and left to cool 
slowly ; the edge to which the workman is 
accustomed to file with, is filed to exactly the 
shape for filling the cone of the pivot when 
in a finished state ; the file marks are then 
ground off by grinding with a piece of copper 
plate and oil-stone dust with oil; then provide 
a punch (such as is used by chasers, and can 
be bought at any tool-shop), whose face pre- 
sents the appearance of the cuts on a file — the 
finer the cuts on this punch the better ; the 
ground edge of the file is then chased with 
this punch, held lightly above the file, imbed- 
ding the file-marks transversely the whole 
length of the file, and is then hardened and 
tempered to a light straw color. 

The next file, or the one to be used for 
grinding, must also be softened and must have 
the edge filed exactly the same shape of the 
first file, and is also to be ground, but in a 
direction perpendicular to its length, and is 
then hardened and tempered to a dark blue 
color. The other file, or the one to be used 
for burnishing, is also softened and must also 
have the edge filed off to exactly the same 
shape as the first file, and is ground first with 
a piece of copper plate with oil-stone dust and 
oil, and lastly with a piece of type metal, with 
very fine oil-stone dust and oil — care being 
taken to grind in a perpendicular direction to 
the length of the file. 

The next consideration is the pivot rest for 



the lathe. A piece of good English cast-steel 
is selected that will exactly fit the hole in the 
lathe for the reception of the pivot rest ; this 
rest is provided with a notched wheel, whose 
object is to keep the rest in a rigid position 
while the repairer is at work thereon ; the 
front part of the rest is thgn turned so that 
a head is left standing, whose breadth should 
be twice the length of a pivot ; this head is 
filed into a number of flats, corresponding to 
the number of notches in the wheel at the 
the back of the rest, care being taken to file 
these flats exactly perpendicular to the point 
opposite in the lathe, when a notch at the 
back of the rest is in check by a piece of steel 
fastened into the base of the lathe ; different 
sized notches are now filed into the flats, in a 
line with the point in the lathe exactly oppo- 
site. The fronts of the notches are now 
rounded, corresponding in shape to the cone 
on the pivot when in a finished state, which 
is done in the following manner : A perfectly 
round file is taken, pointed and provided 
with a collet, and placed in the ordinary 
turning lathe ; or, if the workman is provided 
with an American lathe, the round file is 
screwed into a chuck; in either case the file is 
set in motion and the edge of the notch in 
the rest is brought to bear against it; the rest, 
meanwhile,being slightly moved up and down, 
until the notches have the proper shape, viz., 
corresponding to the shape of the pivot when 
finished; the notches are then ground and 
polished by substituting a round piece of iron 
wire, with oil-stone dust, for grinding, and a 
piece of zinc wire, with diamantine and alco- 
hol for polishing. The rest is then hardened 
and tempered to a light straw color. Now 
the pivot, being turned to very nearly 
the shape it should have, is placed in the 
pivot lathe, so that the front of the pivot 
rests solidly in the notch on the rest, allow- 
ing the cone of the pivot to come as near 
as possible to the rest. The first file is 
then introduced, and the pivot filed until 
the pivot is very near the proper diam- 
eter ; the grinding file is then taken, and 
the pivot ground with very fine oil-stone dust, 
and lastly the pivot is burnished with the 
burnishing file. A little practice will enable 
any one to make a very nice conical pivot. 
In the above description the style of pivot 



212 



AMERICAN HOROLOGICAL JOURNAL. 



lathe supposed to be used is the ordinary 
Jacot lathe, they being the most handy. 
When the pivot lathe differs in style from the 
Jacot lathe, the above description of appli- 
ances will, of course, not apply, but the work- 
men will certainly have ingenuity enough, 
from the above description, to substitute the 
required changes. 

To polish the face of a pinion requires 
a little tool, that can easily be made, thus: 
A piece of brass is filed into the shape 
of a T, with this difference, that the two 
short ends are bent up, and on these ends 
two screws are adjusted; between these, and 
running on these two screws, is a little brass 
piece, through which a hole is drilled, the 
hole being sufficiently large to hold little 
chucks, made of soft iron and brass, that also 
have a small hole drilled through them ; the 
brass piece must be able to revolve freely be- 
tween the screws. Now, when the face of a 
pinion is to be polished, one of the little iron 
chucks is set into the brass piece, the tool 
held in the left hand, and the staff of the 
pinion is put into the ho'e (the hole being a 
little larger than the diameter of the staff of 
the pinion), so that the face of the pinion 
rests against the side of the chuck, and the 
other end of the pinion held against the vice; 
a little oil stone dust with oil is applied to the 
pinion, which is set in motion with the 
drill bow, and ground until a true flat is 
attained; the iron chuck is then replaced by 
one of composition, a little diamantine applied 
to the pinion, and set in motion in the same 
manner, until the pinion is nicely polished. 
The chuck accommodating itself to the face 
of the pinion (it hanging on two pivots or 
screws), must necessarily produce a true flat. 

Charles Spiro. 
33 John street, N. Y. 



GOOD TIME. 



We have received from Mr. F. E. 
Allen one of his patent poising tools, also 
one of the screw stands, and a set of screw 
drivers, but for want of space cannot speak 
of them in detail. It always gives us pleas- 
ure to notice any thing that is calculated to 
assist the workman in doing his work better 
and with greater ease to himself. We think 
they will be well received by the trade. 



Below we give the results of observation 
of the running of Watch No. 1818, manufac- 
tured by the U. S. Watch Company, from 
Dec. 13th to Jan. 13th, taken at irregular in- 
tervals, at which date we carelessly let it run 
down. 

December 13 4.5 seconds slow. 

15 8 

19 6 

27 4 " " 

30 6 

31 5 

January 4 1 " " 

5 1 

9 1 

13 3 

The observations were not taken with a 
view of publication, and it is no more than 
justice to the watch to state that the test was 
not a fair one, as the winding was irregular — ■ 
from nine to twelve o'clock. The running 
down seems to have proved a disturbing 
cause, for now it has a daily losing rate, but 
so uniform that the result is actually better, 
although the loss is nearly two seconds per 
day. The only true test of any time-keeper 
is in its daily rate — not in its showing the 
correct time once a week, once a month, or 
once a year. When we take into considera- 
tion how many disturbing causes there are to 
affect the pocket time-piece — the numberless 
jars it receives in the course of the day, as 
well as the frequent changes of position it is 
subject to — and then consider the fact that 
each twenty-four hours of time is subdivided 
into nearly four hundred and fifty thousand 
separate and distinct parts, each one of which 
is marked by a vibration of the balance, we 
can only look upon it in wonder and admira- 
tion, considering it, as it really is, the nearest 
approach to perfection in engineering skill 
the world ever saw. 

The manufacture of watches in this coun- 
try is of very recent date, and was commenced 
under the most embarrassing circumstances, 
the projectors of the enterprise having very 
little practical knowledge of the business, and 
there being absolutely no skilled labor avail- 
able ; yet all the American factories h ive 



AMERICAN HOROLOGICAL JOURNAL. 



213 



produced work of •which they may well be 
proud. 

Since the above was in type we have re- 
ceived from Messrs. Richard Oliver & Balen 
the following certificate. If the " H. G. Nor- 
ton" was compared with Dudley Observatory 
time every day, and at no time showed a 
greater variation from mean time than one 
second, we should think W. H. Williams & 
Son would have no hesitation in recommend- 
insr the H. G. Nortons to their customers : 

Messrs. Richakd Oliver & Balen, 

Gen'l Agents K Y. Watch Co. : 
Gents, — One of your three-quarter plate 
watches named "H. G. Norton," which we 
bought of you in the early part of November 
last, we ran for four weeks by Dudley Obser- 
vatory time, and it varied only one second 
during that time. We also ran one of your 
" Albert Clark " movements, and it ran nearly 

as close. 

W. H. Williams & Son. 

Albany, Feb. 14, 1871. 



DONATION TO THE MUSKUM OF THE LAND 
OFFICE. 

The Acting Commissioner of the General 
Land Office has received from J. Dickinson, 
Esq., of New York, for the Geological Museum 
a suite of classified specimens of diamond 
carbonate, bort, and diamond bort, in their 
proximate stages of formation, together with 
some carbon dust, produced by abrading one 
piece of carbon or diamond against another, 
in the process of shaping for ornamental and 
other purposes. The ordinary or white dia- 
mond has of late been used for drilling, turn- 
ing, and dressing stone, as well as for placing 
and boring steel and other metals, but the cost 
has been a great objection to its extended ap- 
plication; the diamond carbonate, or black 
diamond, has been substituted, which also 
has the further advantage of being consider- 
ably harder than the white transparent dia- 
mond, and consequently has been applied to 
shaping and polishing the latter. The 
shaping of diamonds for ornamental purposes 
is comparatively a modern art. History in- 



forms us that Louis Van Bergen, of Burges, 
in 1456, first invented a process for cutting, 
then polishing, abrading one diamond 
against another, and by polishing them after- 
ward with the powder produced therefrom. 
This is said to be one of the earliest patents 
granted. After careful research and inquiry 
both here and in Europe, it was found that 
neither the opaque, black, nor transparent 
diamond had ever been shaped into angular 
forms for the mechanical arts. 

The merit of this invention belongs to Mr. 
Dickinson, and the Land Office is especially 
indebted to Dr. Ott, of New York, for his ex- 
ertions in obtaining this valuable donation to 
the Museum connected with the General 
Land Office. 



JEWELKT PEDDLERS. 

Editob Horological Journal : 

I know that I shall touch a sore spot in the 
feelings of nearly every country watchmaker 
when I allude to that bane of their exist- 
ence — the jewelry peddler. 

Flitting from place to place as trade grows 
dull or a better prospect appears, travelling 
from house to house in a manner compelling 
every one to at least look over their goods, 
they are — and why attempt to deny it? — 
most formidable rivals to the small dealer in 
the country. That they are, as a class, a 
nuisance -in any community every watch- 
maker will readily admit ; so, also, will all 
others as well who understand the sub- 
ject. 

The jewelry peddler is subject to very few 
incentives to fair dealing, or restraints against 
very sharp practice. The goods he deals in, 
next to horse-flesh, are perhaps the most 
suited to deceive ; and his comings and 
goings hinder him from being called to a 
prompt account, sometimes forever prevent- 
ing it. With them "all is gold that glit- 
ters," and their rates of profit are fixed 
only by the gullibility or means of their 
customers. The communities in which they 
trade derive nothing from them in the way 
of taxes, although the local dealer always 
has his taxes to pay, and nothing from the 



214 



AMERICAN HOROLOGICAL JOURNAL. 



circulation of the money in their own neigh- 
borhoods. The only thing that can be said 
in favor of the jewelry peddler is, that they 
are too clever to be bores. 

The principal remedy for this state of 
things is of course with the people them- 
selves ; whether it will ever be remedied is a 
matter of doubt. Still a great deal can be 
done by the watchmakers to drive them off. 
In this State (New York) a license fee of $20 
is required for peddling goods of foreign 
manufacture, which covers most watches and 
spectacles, and some other goods. Any citi- 
zen can demand to see a peddler's State 
license, and if he refuses to show it, he can 
take him before a justice of the peace and 
have him fined $5. If it turns out that he 
has no license to show, he is fined $25. The 
licenses are granted by the Secretary of 
State, at Albany, and justices of the peace 
are furnished by the county clerk of their 
county with lists of all licensed peddlers. 
Some years there are not more than twenty 
licensed peddlers in the whole State. It 
should be a satisfaction to every tax-paying 
watchmaker to know that these men were 
compelled to pay their share of the State 
taxes, wlrch would really amount to a con- 
siderable sum. But the best way to oppose 
them is for the local dealers to keep the 
best stock that their means will allow. No 
good watchmaker ought to try to compete 
with peddlers, fancy-goods dealers, stationers, 
and the hosts of others who trade in brass 
and cheap plated jewelry, and horn, and 
wood, and such stuff. If he has only a little 
money, let him deal only in watches, and, as 
his capital accumulates, add other staple 
goods, and let them only be good ones. It is 
far better to earn money by good work than 
to waste valuable time in trying to sell a 
poor article at a cheap price, which will never 
give satisfaction, no matter how cheaply it 
may be sold. "Watchmakers are always held 
to a more strict account for their representa- 
tions than other dealers in the same kind of 
goods, and very properly, too, for they know 
the quality and value of the articles that they 
sell. This fact alone should convince any 
one that a poor article should not be sold at 
all, it being far better to let some one else sell 
the poor goods. 



As long as a watchmaker has not -a good 
stock of watches, gold jewelry, clocks, silver 
and plated ware, and spectacles, he should 
avoid all other goods and confine himself 
strictly to his own class of trade. If with a 
good stock of such things on hand, and 
money to spare, why then he is a very for- 
tunate man, and neither peddlers nor cheap 
jewelry will disturb his peace of mind. This, 
in my opinion, will go some way towards 
driving off peddlers. That they should be 
prohibited by law perhaps would be re- 
quiring too much ; still the license fee might 
be raised to $250, which would not exceed 
the average rent which watchmakers are re- 
quired to pay for their stores in the country, 
so that it would be no great hardship, and 
would tend to save the public from the least 
responsible of the peddlers. But alas ! our 
fraternity have no "lobbyist" at Albany, and 
in case of a struggle, I don't know but the 
peddlers would overpower us there. 

B. F. H. 



QUERY. 



Editor Hoeoi-ogical Journal: 

In your September issue, p. G2, there are 
directions for sizing pinions b t y measuring the 
teeth of the wheel. Rules of this kind may 
be resorted to in all cases where no better 
means are to be disposed of ; certainly, they 
have no claim to giving the exacl sizes of pin- 
ions. But what strikes me most of all in this 
table, is the statement that the pinions from 
G to 8 leaves and those of 12, 15, and 16, must 
be considerably larger for clocks than for 
watchwork. I always thought the mechani- 
cal laws for a correct transmission of move- 
ment by toothed wheels must be absolutely 
the same, no matter whether it forms a part 
of mill work or watch work. If, in a scientific 
organ like yours, such a statement passes un 
noticed, it may lead to the belief that it is a 
dogma generally accepted by all its readers, 
and therefore I wish to ask : 

1. By what reasons ought certain pinions 
to be larger when intended for clock-work ? 

2. On what grounds may certain other pin- 
ions be exempt from this necessity ? 

Saxon. 



AMERICAN HOROLOGICAL JOURNAL. 



215 



ANSWERS TO CORRESPONDENTS. 



H. N. R., Kansas. — There is no greater 
error entertained by the majority of our trade, 
who have not had the advantage of thorough 
education to the business, than that which 
supposes there must be some great mystery, 
some profound secret in polishing steel work. 
There is no mystery — no secret process, nor 
material, it is only patient labor, and that is 
the " secret " of all excellence in any depart- 
ment of art, science, or mechanics. 

Take any simple, beautiful, easy-flowing 
versification; it reads so smoothly that it 
seems possible for any body to have written 
it. But could you see the manuscript of the 
author — perhaps dozens of them — with all 
the erasures, alterations, interlineations, that 
consumed weeks of time, and intense mental 
exertion, you might then change your mind 
as to the spontaneous gushing of poetry. 
So with a picture, that appears so small for 
the price. $1,500 for a landscape 10 by 12 
inches seems a fearful sum, but it is the labor 
bestowed on it that makes it so perfectly true 
to nature, and so highly prized; 'tis not in- 
spiration, 'tis not slight of hand, but down- 
right hard Work. When a musician sits 
down at the piano, sweet sounds follow with 
such easy rapidity that the years of labor to 
acquire that skilful execution are lost sight 
of. An unskilled wood-worker will fancy that 
the exquisite polish on the case of the piano 
is put on by some peculiar varnish — to find 
which has been his inquiry for years. Did 
he but know that the finish he so much 
admires was only the result of labor — nothing 
but persistent hard rubbing — he would per- 
haps go to v}ork instead of spending his time 
in the vain search for some short "royal 
road " to such perfection of polish. It's the 
same with the polish of steel work. Your 
work must be finished with file or graver, or 
whatever other tool is used; the marks of that 
tool must be stoned out, not a scratch or mark 
left; if there be you may polish till the 
" crack o'doom," and all in vain. Then the 
stone marks must be eradicated by fine emery, 
crocus, sharp, or whatever else you use; then 
you can hppe to make a polish with rouge 
and nibbing, rubbing and rouge. You may 
as well expect a mill to grind without power 



as to expect any polish without labor. The 
error usually made is in not preparing for 
i he polishing, a gloss being very quickly given 
when the necessary preliminary steps are 
taken. The labor mostly is in the first pro- 
cess, not the final one. Vienna lime is largely 
used with water to give the final gloss to soft 
steel work. Rouge is most commonly used ; 
diamantine is also used, and gives rapid re- 
sults when all the previous preparation of the 
work has been well done. All labor in polish- 
ing is lost ; it requires no labor. The labor 
of preparing to polish is not lost ; it is all 
spent necessarily, because no good results 
can be had without it. 

0. D. B., New York. — A Chinese duplex 
watch, with centre seconds, would be better 
than an ordinary watch for taking transit 
observations of the sun only because the sec- 
onds are larger. 

The best thing for that purpose, of course, 
is a chronograph ; but the expense of such 
an instrument places it beyond the reach of 
the watchmaker. The next best thing is a 
good chronometer, beating half seconds. 
With practice no assistant is needed in 
taking an observation ; by carrying the beat 
in the mind, and noticing between what beats 
the contact of the edge of the sun takes place 
with the liHe, the exact time of such contact 
may be noted to a very small fraction of a 
second. Messiie. John Bliss & Co., the chron- 
ometer and transit makers, inform us that 
very little experience is required to enable 
any person to note the contacts, using such a 
chronometer as we mention, within one 
quarter of a second, and that even greater 
accuracy is attainable. But for the practical 
purposes of the watchmaker it is not neces- 
sary to note them closer than the nearest 
second. 

E. N., Ct. — Authorities on this subject 
differ in opinion as to the proper means of 
producing the curve in the Breguet hair- 
spring. The end to accomplish is a perfect 
isochronism ; some produce the curve by 
making two, and sometimes three, kinks in 
the spring ; others produce the curve by a 
gradual sweep towards, and then concentrio 
to, the centre, and without any kink what- 
ever. In our opinion, the latter mode ia 
much to be preferred, there being no inter- 



216 



AMERICAN HOROLOGICAL JOURNAL. 



ruptions in its action, as there certainly must 
be where kinks are resorted to to produce 
the curve. 

E. L. M., 0. — "We have received several 
letters recently, speaking of the necessity of 
some means for the better education of 
watchmakers in matters pertaining to their 
profession, and, judging from specimens that 
a friend says he meets with almost daily on 
the road, should say there was. We append 
an extract from his last letter : 

"A * travelling jour.' applied to a friend of 
mine for a job. He was of the German per- 
suasion. He told a pitiful story of being 
unfortunate, sick, and, worst of all, out of 
money. My friend consented to give him a 
few jobs to help him along. The first was an 
old-fashioned verge watch, which he put in 
order, and handed back for ' inspection.' It 
was apparently well done. But upon exami- 
nation with a glass, a Uttle moisture appeared 
on the contrite pinion. Upon inquiry what 
that was, he replied, ' De reel vas loose ; I 
put a little acit on him, and he rust and go 
tight.' His first job was also the lad. 

" I was selling one of my customers some 
'material,' occasionally suggesting some- 
thing he might need. Amongst other things, 
I asked him if he did not want some ' centre 
squares.' He said, 'I not puy tern any 
more.' I inquired if he did not find occa- 
sion to use them. He said, 'Oh, yes.' 
' Well,' was my reply, ' What do you do 
then ? ' He said, ' I use dese little shingle 
nails ; I files 'em town.' " 

H. U., ///. — If you will refer to the answer 
to W. W. S., page 69, Vol. II., you will find 
the information you desire in regard to pla- 
ting- , ' 

AMERICAN HOROLOG-ICAL JOURNAL, 

PUBLISHED MONTHLY BY 

C3-- IB- MILLER, 

229 BrO($dwatj, JV. Y., 
At $2. 50 per Year, payable in advance. 

A limited number of Advertisements connected 
with the Trade, and from reliable Houses, will be 
received. 

J®"" Mr. J. Herrmann, 21 Northampton 
Square, E. C, London, is our authorized Agent 
for Great Britain. 

All communications should be addressed, 
O. B. MILLER, 
P. 0. Box 6715, New York. 



EQUATION OF TIME TABLE. 



GREENWICH MEAN TIME. 



For March, 1871. 



Day 



w. 

Th. 
Fri 
Sat 
Su. 
M.. 
Tu. 
W. 
Th. 
Fri. 
Sat 
Su. 
ML. 
Tu.j 14 
W.| 15 
Th.! 16 
Fri J 17 
Sat 18 
Su. 19 
ML. 20 
Tu.l 21 



W. 
Th. 
Fri 

Sat 
Su. 
M. 
Tu. 

\y. 

rii. 

Fri 



Sidereal 
Time 
of 
the Semi- 
diameter 
Passing 

the 
Meridian. 



Equation 

of 

Time to be 

Added to 

Apparent 

Time. 



65 43 
65 36 
65.29 
65 22 
65.16 
65.10 
65.(14 
64.98 
64.93 
64 88 
64.83 
64.78 
64.74 
64 70 
64 66 
64 63 
64.60 
64 56 
64.54 
64.52 
64 50 
64 48 
64.47 
64.46 
64 46 
64.46 
64 46 
64.46 
64.47 
64.48 
61 49 



12 35.62 

12 23.51 

12 10.88 

11 57.77 

11 44 20 

11 30 18 

31 15.74 

11 0.91 

10 45 70 

10 30.16 

10 14.29 

9 58.11 

9 41.65 

9 24.93 

9 7 98 

8 50 81 

8 33.43 

8 15.87 

7 58.14 

7 40 26 

7 22.25 

7 4.13 

6 45.91 

27.60 

9.22 

50.81 

2.36 

13.89 

55.44 

37.02 

18.64 



6 2 


6 


5 5( 


5 3: 


5 1. 


4 5. 


4 3 _ 


4 If 



Equation 




of 


DilT. 


Time to be 


for 


Subtracted 


One 


from 




Mean Time. 




M. S. 


s. 


12 35 73 


0.494 


12 23.61 


0.515 


12 10.99 


0.536 


31 57.88 


0.555 


31 44.31 


0.574 


11 30.28 


0.592 


11 15.85 


0.610 


11 1 02 


0.626 


10 45.81 


0.641 


10 30.27 


0.655 


10 14 40 


0.668 


9 58 22 


0.681 


9 41.76 


0.692 


9 25.04 


0.702 


9 8 09 


0.711 


8 50.92 


0.719 


8 33 54 


0.728 


8 35.97 


0.735 


7 58.24 


0.742 


7 40.36 


0.748 


7 22.35 


0.753 


7 4.23 


0.757 


6 46 00 


0.761 


6 27 68 


0.765 


6 9.30 


0.767 


5 50.88 


0.768 


5 32.43 


0.769 


5 13.96 


0.769 


4 55.51 


0.768 


4 37.08 


0-766 


4 18 69 


0.763 



Sidereal 
Tima 

or 

Right* 

Ascension 

of 
Mean Sun. 



H. M. 

22 35 
22 39 
22 43 
22 47 
22 51 
22 55 

22 59 

23 2 
23 6 
23 10 
23 34 
23 18 
23 22 
23 26 
23 30 
23 34 
23 3-t 
23 42 
23 46 
23 50 
23 54 
23 58 

2 
6 
10 
13 
17 
21 
25 
29 
33 



23.76 
20.32 
36.87 
13 42 
9.97 
6.53 
3.08 
59.63 
56.19 
52.74 
49.29 
45.85 
42.40 
38.95 
35.50 
32.05 
28.61 
25.16 
21.71 
18.27 
14.82 
11.37 
7.92 
4.48 
3.03 
57.58 
54.13 
50 69 
47.24 
43.79 
40.35 



Mean time of the Semidiameter passing may be found by *ub- 
tracti ig 0. 19 s. from the sidereal lime. 

The Semidiamet'jr lor mean neon may be assumed the samju 
that for apparent uoon. 

PHASES OF THE MOON. 

D H. M. 

© Full Moon 6 15 39.2 

( Last Quarter 13 10 19.8 

© New Moon 20 10 5 

) FirstQuarter 28 18 44.3 

D. H. 

( Perigee v . . 30 9 6 

( Apogee 26 4.3 

o / // 

Latitude of Harvard Observatory 42 22 48.1 

H. M. 8. 

Long. Harvard Observatory 4 44 29.05 

New York City Hall .■ 4 56 0.35 

Savannah Exchange .. 5 24 20. 572 

Hudson, Ohio * 5 25 43.20 

Cincinnati Observatory . 5 37 58.062 

Point Conception 8 142.64 







APPARENT 


APPARENT 


MKRID. 






R. ASCENSION. 


DECLINATION. 


PASS AGS. 




D. 


H. M. S. 


o ' / 


H. M. 




1 


2 58.23.. 


..- 56 2.9.. 


... 1 27.6 


Jupiter. . . 


. 1 


5 3 37.72 . 


.. + 22 63 41.5.. 


... 6 27.2 


Saturn, . . 


. 1 


18 34 42.3'.. 


.. -22 24 63.1.. 


...19 56.3 



AMERICAN 



Horolosical Journal. 



Vol, II. 



NEW YORK, APRIL, 1871 



No. 10. 



CONTENTS. 

essat on the construction of a simple and 
Mechanicallt Perfect Watch, ..... 217 

Heat, 223 

The Pendulum as Applied to the Measurement 

of Time, 228 

Niceel, 234 

Watch Brass, 236 

Answers to Correspondents, 238 

Equation of Time Table, 240 

* * * Address all communications for Horological 
Journal to G. B. Miller, P. 0. Box 6715, Aeto York 
City. Publication, Office 229 Broadway, Room 19. 

[Entered according to Act of Congress, by G. B. Miller, in tbe 
office of tbe Librarian of Cougress at Wasbington.J 

ON THE 

CONSTRUCTION OF A SIMPLE AND MECHANI- 
CALLY PERFECT WATCH. 



BY MOEEITZ GROSSMANN. 



CHAPTER V. 

THE TRAIN. 

53. The first condition for tbe construction 
of the train of a watch is, to make it of as 
large dimensions as the diameter of the 
movement will admit of. The very limited 
space allowed by the reigning taste for the 
movement of a portable time- keeper is already 
an impediment to the attaining of a high 
degree of perfection in the gearings ; and if 
it is possible to execute the wheels and 
pinions of a clock with a satisfactory degree 
of accuracy, it gets more and more difficult 
to do so according to the smaller dimensions 
in which the work is to be executed. If we 
had the means of verifying easily the accu- 
racy of the division and rounding of our small 
pinions, even of the best make, we wou 1 d soon 
come to the conclusion that it must neces- 
sarily diminish with their dimensions. The 
inequalities and alterations of shape by the 
stoning and polishing will be nearly the same 



with a large pinion as with a small one, 
only the small one suffers proportionally 
much more under them. This applies to the 
manufacturing of the pinions; but before the 
pinion runs in the train, it has to pass through 
the finishing process. The finisher, first of 
all, will have to verify whether the pinion 
runs perfectly true, and to set it true in case 
of need. In a]l operations of this nature the 
operative has to rely on his eye for distin- 
guishing whether the state of the piece is 
satisfactory. But the eye, like all the senses 
of man, is reliable only within certain limits, 
and if a good workman pronounces a pinion 
to be true, this statement must not be taken 
mathematically ; it can only be understood 
so that an experienced eye can no more 
detect any deviations from the truth of run- 
ning. There are, then, in any piece of work- 
manship some small defects escaping the 
most experienced eye, and their absolute 
quantity is about the same for the large 
pieces as for the small ones. Let us suppose, 
for instance, that a careful workman, when 
turning a pinion of 3 m. diameter, cannot 
perceive any defect of truth beyond one- 
hundredth of this size — say 0.03 m. The 
same defect, indistinguishable to his eye, with 
a pinion of 1 m. diameter will be, not one, 
but three-hundredths of it ; consequently it 
is of threefold more importance with the 
small pinion, taken proportionally. 

The same considerations will, to their full 
extent, apply also to the correctness of the 
depths, or gearings ; and it will be clearly 
seen that it is of the greatest importance to 
construct the acting parts of the train as 
large as the diameter of the watch will admit 
of. 

54. Another matter of great importance is 
the uniform transmission of motive power 
from the barrel, through the train, to the 
escapement. This uniformity can only be 
attained by gool depths ; an 1 as it is well 



218 



AMERICAN HOEOLOGICAL JOURNAL. 



known that the depths are more perfect with 
the higher numbered pinions, it is advisable 
never to have the centre pinion with less 
than 12 leaves, the 3d and 4th wheel pinions 
with 10, and the escape pinion with 7 at least. 
The difference resulting therefrom in the 
cost of manufacturing is so very trifling that 
it could not be an obstacle to making even 
low class watches with these numbers. 

The centre pinion, it must be admitted, 
will be more delicate, apparently, and more 
liable to injury by the sudden jerk resulting 
from a rupture of the main-spring, or by the 
pressure occasioned through careless wind- 
ing. The teeth of the barrel, too, being ne- 
cessarily thinner, will be more apt to bend 
from the same causes ; but this is partly 
remedied by the fact that with a pinion of 
12 there are in almost every movement two 
teeth of the barrel acting at the same time 
on two leaves of the pinion; while in the 
lower numbered pinions one tooth alone has 
to lead through a more or less extended 
angle. Thus, any sudden shock will be 
divided between two teeth of the pinion of 12, 
and sustained in the same way by two teeth 
of the barrel belonging to it, whereby the ap- 
parent danger is greatly diminished. Besides, 
the finer toothing producing a better trans- 
mission of power, a weaker main-spring may 
be used, and in case of its rupture the shock 
will be less violent. 

55. One of the chief conditions for a good 
and regular transmission of power is a good 
and suitable shape of the wheel teeth; and it 
is astonishing to see in what an indifferent 
way this important matter is treated. It is 
a well-known fact that the wheel teeth, in 
order to act properly, ought to have an 
epicycloidal rounding, and no engineer would 
suffer any other form for the teeth of star 
wheels. Berthoud treated this subject in a 
most elaborate way about a century ago ; 
Reid anl others have also explained the 
principles of the construction of toothed 
wheels most explicitly, but in vain. It seems 
that the greater part of the Horological com- 
munity have resolved to view the shape of 
their wheel teet as a matter of taste. All 
the wheels of English and other makers have, 
with very few exceptions, then." teeth of a 
shape defying the rules of Berthoud, Reid, 



and other leaders ; a shape of which nothing 
can be said, except that they look very nice 
in the eyes of those that make them, or those 
who use them, and say, " They look much 
better, indeed, than those ugly pointed 
teeth." There is no possibility of being suc- 
cessful against arguments like these, and I 
have known many a respectable and good 
watchmaker who declared that he could not 
bear the sight of epicycloidally rounded teeth. 
This is a subject, however, which can not be 
more amply entered into for the moment, but 
if our Editor wishes it, and if the present 
little treatise is favorably received by his 
readers, I shall be ready to make it the sub- 
ject of another treatise, closely following the 
present one, and extending to the different 
ways of cutting wheels and pinions, practical 
methods of finding the sizes of wheels and 
pinions, and the distance of pitch, as well as 
the eight sizes of cutters for a given diameter 
and number of teeth; all by easy and plain 
calculation and measurement, with tables for 
greater convenience. 

56. The respective proportions of the 
wheels of a train ought also to present a cer- 
tain harmony, attainable by a regular pro- 
gression in the diameters of the wheels and 
the fineness of their teeth. 

57. With respect to the escape pinion, at 
least for the larger watches, I would strongly 
recommend to have it of 8 leaves, with a 
fourth wheel of 75, and an escape wheel of 
16 teeth. The last depth, the most sensitive 
of all to any irregularity of transmission, will 
be found greatly improved by so doing. 

58. The following are the sizes of a train, 
which, according to nay opinion, would 
answer perfectly to the above conditions, for 
a watch of 43 m.=19 lignes Swiss, or 14 Eng- 
lish size : 

Diameter of barrel (25) 43.0.485=20.85 m. 

Centre wheel 15.4 " 

Third " .... 13.0 " 

Fourth «' 11. 8^ " 

The numbers would be : 

Barrel, 90 teeth, Pinion, 12. j 

Centre wheel, 80 " " 10. 

Third ■' 75 " " 10. 

Fourth •■ 75 " " 8. 

The sizes of teeth are accordingly : 

Barrel 0.345 m. 

Centre wheel 0.30 " 

Third " 0.27 " 

Fourth " ; 0.24 " 



AMERICAN HOROLOGICAL JOURNAL. 



219 



It is easy to see that this progression is a 
very regular one. 

59. The train ought to be arranged in such 
a way as to have the seconds circle at a suit- 
able place on the dial. This circle, of course, 
ought to be as large as possible, for the sake 
of distinctness of the divisions ; and, on the 
other hand, it ought not to be so large as to 
cover entirely the VI. of the hour circle. It 
may. be recommended as a good disposition 
to have the centre of the circle of seconds 
exactly in the middle of the distance from 
the centre of the dial to its edge. The 
general observation of this rule would be a 
decided step towards a greater regularity of 
construction, and, besides, it would prove a 
great boon to all the dealers and manufac- 
turers of dials, and to all the repairers who 
have to replace broken dials. 

A greater circle of seconds might be at- 
tained by approaching its centre nearer to 
the centre of the dial, but this subordinate 
advantage would be too dearly purchased at 
the expense of the commodious arrangement 
of the wheel work. . 

GO. The height of the moving arbors ought 
Fig. 16. 



to be restricted only b} r the height of the 
frame. The longer the distance between the 
two bearings of an axis can be, the better it 
will prove for the stability of the moving 
part, as well as its performance. The same 
amount of side shake required for free action 
will influence the pitch of a long pinion less 
than that of a short one. 

The diameters of the pivots in watch-work 
could not be made according to the generally 
established rules in the construction of ma- 
chines, for if we should attempt to make the 
dimensions of our pivots in a theoretical pro- 
portion to the strain which they have to 
i-esist, we would obtain pivots of such ex- 
treme thinness that they would be very dif- 
ficult to make and to handle, and it would be 
doubtful whether the cross section of such a 
pivot would not come into an unfavorable 
proportion with the molecular disposition of 
the steel. Besides, it ought always to be 
kept in mind that the pivots of the train must 
not be calculated to bear with safety the mere 
pressure of the main-spring, but also the 
sudden strains resulting from rupture of the 
spring, or from rough winding. Thus, there 
Fig. 17. 



will be very little to say against the way in 
which the pivots of watch-work are generally 
made. 

61. There remains a word to say on an im- 
provement of recent date. It has already 
been mentioned (54) that the centre pinion 
and the barrel are in constant danger of 
having their teeth bent or broken by the 
sudden jerk of a breaking main-spring. These 
accidents are so troublesome, that a number 
of little contrivances have been made in order 
to avoid them. It will not be useless to give 
a look and a thought to these inventions, and 
to consider whether they are really what 
they ought to be. 



62. There is one of these precautions con- 
sisting of a kind of elastic transmission on 
the third wheel. This wheel (Figs. 16 and 
17) is fitted with a collet, loose on the pinion, 
which carries a disc, b, riveted to it. On 
this disc is fastened a spring, c, with a per- 
pendicular arm, d, which extends towards the 
third wheel, and reaches the arms of this 
wheel with its end, thus carrying the wheel 
with it while the watch is going. The end of 
the arm has a slight slope, and when the 
spring breaks it is expected to slip over the 
arm of the wIipp 1 by the violence of the shock, 
and thus to . top it. I should not advise the 
use of this safety apparatus, because I think 



220 



AMERICAN HOROLOGICAL JOTTBNAL. 



it will fail by the inertia of the parts between 
the third wheel and the main-spring. The 
destruction, by a sudden jerk, will be com- 
pleted before its power reaches the third 
wheel, in a like manner as the blast powder 
in a hole made in solid rock, and stopped up 
with a little clay, will split the rock by its 
sudden action before it has time to drive out 
the small stopping. Besides, this arrange- 
ment, if it should have any chance of success, 
must have the spring exactly regulated, so 
that it does not yield to the pressure of the 
main-spring when fully wound, but that any 
pressure beyond this will make it slip over. 
If this be not the case, the safety of the 
centre pinion will not be attained ; and, if it 
be, any excess of -pressure, by inconsiderate 
winding at the end of the operation, will 
make the spring run over, and the result of 
this would be a deviation of rate. Now, I 
think the wearer of a watch will find an 
irregularity of its performance a fault of a 
much more grave character than an occa- 
sional accident which he knows to be out of 
connection with the time-keeping of the 
Avatch. 

G3. Other contrivances promise better suc- 
cess, because the regulating resistance is in 
the centre pinion. This latter has a rather 
large hole, and is adjusted on a staff or axis, 
to which the wheel is riveted, the pinion 
being held fast on the staff by a screw nut 
and a washer. This pinion, if it is set in 
motion, performs like a solid one, owing to 
the frictioual resistance which keeps it to its 
staff, being a little in excess of the strain 
effected on it by the moving power ; but any 
addition to this strain causes the pillion to 
move independently of its staff, and thus to 
counteract the strain without injury to any 
of the acting parts. It will be readily under- 
stood that this disposition protects the centre 
pinion and barrel teeth, not only against the 
sudden shocks of a breaking spring, but also 
against any unequal strain in winding, and 
all this without any alteration of the time 
shown by the watch (62). 

However, this contrivance has also its weak 
side. The centre pinion, with its large hole, 
especially when it is of a lower number than 
12, has too little stock left between this hole 
ami the bottom of "the teeth, and therebv the 



solidity is endangered from another side. 
Therefore, it will answer in the case of a 
watch the hands of which are set at the front, 
but it will hardly do for the hollow centre 
pinions used for setting the hands on the 
back. 

64. I recently had in hand a similar safety 
centre pinion of English make, also with a 
staff on which the pinion was screwed with a 
three headed screw. Tapped into the hole of 
the pinion, and cut on the staff, this screw, 
which must be a right handed one, if the 
centre wheel is above the pinion, and a left 
handed one' if it is below the pinion, is kept 
tight in the ordinary course by the pressure 
of the motive power. But when a backward 
shock is applied to the pinion, it unscrews, 
thus obviating any injurious effect. This 
method, though it appears very effective; is 
still open to several serious objections. The 
additional strain at the end of the "winding 
operation is not counteracted, but tends to 
screw the pinion still closer, so that it is 
doubtful whether, in case of emergency, it 
wpuld break or unscrew, especially consider- 
ing that the pinion itself, by the large dimen- 
sion of its hole, is rendered, rather frail. 
Besides this, there is no saying from which 
side the shock of the breaking spring will 
come. If the spring breaks near its outer 
end, the shock will apply in the way of the 
regular tension of the spring, and the safety 
apparatus will be of not the slightest use ; on 
the contrary, the pinion weakened by the 
large hole, will stand a poor chance. It will 
only be effective in case of the spring break- 
ing near its inner end. 

65. There is a general demand for any- 
thing effecting a guard against acccident to 
the centre pinion, and every thinking manu- 
facturer ought to make this an object of his 
reflections. Still, it seems the right thing is 
not found yet. The best contrivance is cer- 
tainly that of adjusting the pinion on a round 
and slightly taper staff, and to hold it fast by 
a screw nut and washer; but it has the objec- 
tion of diminished solidity of the pinion 
itself against it. 

66. I never felt a temptation, however, to 
apply it to any watch of my own manufac- 
ture, as I believe that there is a plainer way 
of attaining the purpose. First of all, it will 



AMERICAN HOROLOGICAL JOURNAL. 



221 



lead in the direction of having, by observa- 
tion of the preceding principles concerning 
barrel and train, a main-spring of compara- 
tively great length and little thickness. In 
case of breakage, the shock resulting from it 
will be less injurious, and in winding it the 
interposing of the stopwork will be more 
readily felt than with a strong stubborn 
spring. 



Secondly, I think it advisable, and practi- 
cally possible, to strengthen the teeth of the 
centre pinion and barrel by giving them a 
shape more appropriate to their functions. 
Whenever one of these teeth is broken, the 
fracture invariably takes place at the bottom, 
where it is thinnest, and has two sharp cor- 
ners, required by the taste of the great ma- 
jority of watchmakers. An alteration of this 



Fig. 11 




shape would give the teeth about double the 
strength, as it will be evident when looking 
at the dotted lines marked a in the cut, with- 
out interfering in any way with the service of 
the parts. I feel persuaded that the general 
employment of this form for the teeth of 
barrels and centre pinions would serve the 
purpose very well, though it is not pretended 
that a complete guarantee against fracture 
would ensue from it; but in this point all the 
other contrivances are equally doubtful. 

CHAPTER VI. 

THE MOTION-WOBK. 

67. There is not much to say about the 
construction of this part of the movement, 
because it is, to a certain degree, independent 
of the proportion of the train. In Swiss 
watches the motion works are generally 
much smaller than there is any necessity for 
making them. With the employment of the 
free springs, however, there might be some 
advantage in very small motion work, be- 
cause the barrel heads of that kind have no 



shoulders allowing the necessary space for 
the hour wheel. 

08. There are some trifling matters in the 
motion-work open to reform. In English 
watches, even of the better makers, the 
minute wheel moves mostly on a brass pin, 
driven rather carelessly into the pillar plate ; 
an execution altogether unworthy of the char- 
acter and general workmanship of these 
watches. The Swiss watches, on the con- 
trary, down to their lowest qualities, have 
invariably a screwed staff on which the 
minute pinion is adjusted. These staffs are 
not easy to make, inconvenient to take out 
and screw in again, and by the tapping of the 
hole in the plate they offer less reliability of 
a true pitch than a round hole drilled on the 
pitch circle. I think there is a way between 
these two, which is easy of execution, and 
irreproachable as to solidity and diminished 
friction. A hole of the same size as that in 
the minute pinion is drilled through the 
pillar plate, on the pitch circle. A good 
round and well polished pin of hard steel, 
rounded at both ends, is driven into this 



222 



AMERICAN HOEOLOGICAL JOURNAL. 



hole, even with the plate at its inner side, and j 
projecting on the other side till it nearly ; 
touches the dial. The minute pinion has a ! 
small projecting cannon left beyond the rivet 
ing, to hold the minute wheel at a little dis 
tance over the plate. 

Fir.. 19. 




G9. There is another matter which might 
easily be improved ; it is the way of adjust- 
ing the minute hand to the cannon pinion. 
In almost all Swiss watches the hand is ad- 
justed on the end of the setting staff, and 
therefore it is necessary to support the set- 
ting square when putting the hand on, lest it 
should come out of its place by the pressure. 
This is not the case when the hand is adjust- 
ed on the extremity of the cannon pinion, 
which has a shoulder for this adjustment. 
Besides, this arrangement affords the advan- 
tage that the end shake -of the hour-wheel 
can be regulated between the face of the 
cannon pinion and the lower end of the 
cannon of the minute-hand, thus dispensing 
with the small spring commonly in use for 
keeping the hour-wheel steady in its place. 
Fio 20. 




70. It remains only to say a few words 
concerning the setting the hands, which, in 
most cases, is done from behind, in Swiss 
watches. The setting the hands on the dial 
s^ide is an inconvenience almost inseparable 
from the nature of a full plate movement, but 
in I pi. and bridge frames there is not the 
slightest necessity for it. The gradual aban- 
donment of the old plan of cases, with 
fixed domes, and the movement accessible 
only from the dial side, brought the reform of 
the way of setting the hands with it. 



71. The dial of the watch, though of a 
material rather inconvenient to handle, is not 
much open to alterations. The liability to 
injury of the enamel dial has led to many 
endeavors to replace it by some more appro- 
priate material. But the principal considera- 
tion of a good dial, distinctness, has never 
been attained in such perfection as with the 
enamelled ones. A perfectly white surface, 
with deep black figures on it, cannot be sur- 
passed for this purpose. Silver dials, which 
were intended to supplant enamel, have 
nearly the same whiteness when new, but 
they are very liable to get dark from atmos- 
pheric influences or careless handling. Gold 
dials have also been tried, but being much 
less distinct, and especially a gold dial with 
gold figures and gold hands, they may be con- 
sidered a nuisance, as in any place where it is 
not peifectly broad daylight, and to any per- 
son who is not endowed with a very sharp 
sight, it is impossible to derive any benefit 
from a watch fitted out in that way. 

For these reasons, the enamel dial, in spite 
of its fragility and additional thickness, is, 
and will be, kept in use by all those who do 
not leave out of sight its principal purpose ; 
but it cannot be denied that the invention of 
a metallic, or other more appropriate ma- 
terial, possessed of the indispensable qualities, 
would indeed prove a great progress in prac- 
tical horology. There is ample room for use- 
ful inventions. There was a period when, in 
England and elsewhere, dials were preferred 
of a yellowish or grayish tint. These are, of 
course, not so fit for the purpose as those, of 
pure white enamel. In the same way, the 
slightly frosted surface of the English dials is 
thought a great improvement, as it is said to 
allow of looking at the watch in any direction 
vithout being disturbed by the reflection of 
the dial surface. This is a strange mistake, 
for if the dial of a watch does not reflect, 
when held in an awkward direction, the glass 
over it certainly will do so. Besides, it is so 
very easy to look at a watch without any 
danger of annoying reflex. 

72. The fastening of the dial is effected in 
this direction by pins or screws. It is not ad- 
visable to fix the dial with two small screws 
and holes drilled through it, because the dial 
is very much exposed to injury by the slight- 



AMERICAN HOROLQGICAL JOURNAL. 



22< 



est sideward pressure when shutting the case 
— the holes being so very near the edge of 
the dial. This method of fastening dials was 
formerly preferred by the best French and 
Swiss makers, and many a fine dial has been 
spoiled by its 

Another way of fastening the dial is with 
pins. It is quite efficient, and involves no 
danger : therefore it has been much in favor 
in Eaglish watches, and if the movement can 
be got at there is nothing to be said against 
it. But in the movements of the present 
period, the greater part of which do not open 
with a joint, the fastening with pins would be 
rather troublesome, because, for taking off 
the dial, it would be necessary to take the 
movement out of the case. 

In all movements cased in this way, the 
dial pillars ought to be held by key-screwsj 
which allow taking off the dial without re- 
moving the movements. 

A very good method of fastening the dial 
is to set it in a thin rim of silver or gold, and 
adjust this rim nicely on the outer edge oj 
the pillar plate. 

73. The hands, in order to be distinctly 
seen, ought to be of a dark color, and the 
generally adopted blue steel is far preferable 
to gold for this purpose, and the figures and 
hands ought to be a little more substantial 
than the present taste prescribes for them. 
The most convenient shape for the purpose is 
the spade pattern ; the Breguet and the 

Fni 21. 




Fleur-de-Lis hand3 not bo!ng easily distin- 
guisLed. 



74. The circle of seconds ought to have 
every fifth degree visibly marked by a longer 
and stronger stroke, in order to facilitate the 
reading of the seconds. 

Formerly all the dials had flat sec. nds, but 
for about thirty years it has been quite 
common to have sunk seconds, even for in- 
ferior watches. There is some advantage in 
that, especially in flat watches, where it 
affords acommodation for the seconds-hand, 
but at the same time it weakens the dial con- 
siderably. This may be the reason why some 
makers have the sunk part much smaller, and 
the seconds painted on the main dial, the 
lines extending inward to the edge of the 
sink. The seconds-hand is then shorter, and 
moves in the sink. 

The dial ought never to be made larger 
than the pillar plate. 



o- 



1IEAT. 



NUMBER EIGHT. 



FURNACES — FUEL LAMPS — COMBUSTIBLES GAS 

ALCOHOL, ETC. BLOW - PIPES METHOD OF 

USING — CONCLUSION. 

Furnaces differ in construction according 
to the uses for which they are designed. 
The main parts of every furnace are the body 
in which the heat is produced, the grates or 
bars upon which the fuel rests, the ash pan 
for receiving the residue, and smoke-pipe for 
conducting off the gaseous products of com- 
bustion. The subject is one that would oc- 
cupy far too much of our space to go fully 
into it, and we shall only consider one which 
may be termed a universal furnace, and which 
is suitable for almost every operation in the 
work-shop. This universal furnace is of 
cylindrical form — this form being the best 
adapted for producing a high heat with the 
least fuel. It is made of strong plate iron, 
and lined in the body and dome with re- 
fractory fire clay, the body being about four- 
teen inches high by seven inches in diameter. 
There are six doors, one at the base for the 
admission of air, another in the middle for 
the entrance of the fuel, and one for the recep- 
tion of the muffle used in assaying or refining. 
The door in the dome is for the purpose of 



224 



AMERICAN HOEOLOGICAL JOURNAL. 



feeding the fire in crucible operations, and in 
the side and at the top for the reception of 
the neck of a retort. There are two lateral 
openings, opposite to each other, for the pas- 
sage of tubes, or of an iron bar, as a support 
to the rear end of a muffle. The two circular 
openings are those by which it is coupled 
with the pipes connecting it with the flue of 
the room it is placed in, and are closed by 
movable plugs. In crucible operations the 
smoke-pipe should lead from the top open- 
ing, and in evaporations from the aperture in 
the back. The openings in the flue must be 
above the level of the furnace. An opening 
at the base is for the introduction of the 
mouth of a pair of bellows, by which it may 
be converted into a blast furnace if necessary. 
Blast furnaces are serviceable for expedi- 
tiously producing a great intensity of heat,and 
are used for fusions and other operations 
which require more power than can be ob- 
tained by a chimney draught. All furnace 
operations should be conducted under a 
stationary hood, so that the carbonic acid 
and other noxious exhalations may have an 
escape, and the sparks and heated air emitted 
be prevented from endangering the comfort 
and safety of the apartment. 

Coal, coke, and charcoal are the fuel most 
used. Coal is the least available, for it con- 
tains sulphur, and yields a large amount of 
ash and clinker, which choke the grating ; 
and it should, therefore, never be used in the 
blast furnace. Coke and charcoal, separately 
and combined, are used for all the furnace 
operations in the arte; the former being pref- 
erable for higher temperatures. Weight for 
weight, their amount of heat is nearly equal; 
but the greater density of the coke enables it 
to give more, bulk for bulk, by ten per cent 
Charcoal ignites more readily, but coke is 
more durable. Moreover, when of good 
quality and free from sulphurous and earthy 
matter, it gives but little ash or clinker. By 
mixing the two together the good qualities of 
both are obtained; although charcoal alone 
is preferable for some purposes. Before 
using the coke or charcoal care must be taken 
that it has been freed from dust and dirt by 
sifting, and that the pieces are about the size 
of a walnut, so that they may paok away 
neither too loosely nor too compactly. 



Lamps are convenient and economoica 
substitutes for furnaces in small operations. 
Being less cumbersome and more cleanlj 
than furnaces. They are readily manageable 
and always ready for use; and they alst 
afford the means of more rapidly multiplyin;; 
results. The amount of heat to be obtaine I 
by these instruments depends upon theii 
size and arrangement. A properly construct- 
ed lamp may be made subservient to all th i 
requirements of an ordinary workshop. Tha 
heating power of the flame is most active im- 
mediately beneath its summit, and the vessel 
should be gradually brought into direct con- 
tact with that portion, and should be heated 
gradually in proportion to its thickness. 
When thick glass or porcelain, or brittle, 
bad conducting material is suddenly heated, 
the heated part expands while the rest does 
not, and this unequal tension of two adjacent 
parts causes the cracking or fracture of the 
vessel. There is therefore a great advantage 
in employing glass or porcelain vessels of thin, 
structure, for the heat being rapidly conduct- 
ed through them, the liability of fracture is 
diminished. As strength is, however, often 
required, and thicker vessels must be used, 
the above principles of expansion and of con- 
duction must be remembered when they are 
employed. 

In order to apply a small fire to a large 
surface, they may be diffused by setting the 
vessel in a sand or water bath, or, which is 
convenient and more cleanly, a plate of sheet 
metal or wire gauze may be placed between 
the vessel and the fire. It is safer not to allow 
the vessel to touch the plate or gauze. Iron 
or brass gauze may be used, although fine 
copper gauze is preferable, because it is more 
durable. 

Gas is by far the most economical source 
of heat for small operations, it being always 
ready for use, easily manageable and cleanly. 
It may be conveniently led to any part of the 
room through a flexible caoutchouc tube, for 
which purpose one end is fitted with a brass 
nozzle for attaching it to the supply-pipe; the 
other end terminates in either an Argand or 
Bunsen burner, or any other burner suitable 
for the work intended. The Argand 
burner consists of a small circle per- 
forated with a great number of small holes, 



AMERICAN HOROLOGICAL JOURNAL. 



and requires a chimney. The Bvmsen burner 
consists of a metal tube of a suitable shape 
placed on the ordinary gas burner, and four 
or five small holes are cut in the tube a little 
below the gas flame. This burner gives a 
strong heat, and -when properly made has 
little if any smoke that will discolor the 
article that is being heated. A good gas 
flame for blow-pipe operations is made by 
taking out the usual burner and filling up the 
space with a little bunch of small binding 
wire; or still better, if a brass nozzle is put 
in the place of the burner with room enough 
for a bunch of small binding wire larger in 
diameter than the space occupied by the old 
burner would admit of, it will produce a flame 
particularly fitted for blow-pipe operations, 
where a strong heat is required, while by re- 
gulating the stopcock a flame can be obtain- 
ed suitable for the most delicate of opera- 
tions. 

Very neat gas furnaces are made by W. F. 
Shaw, of Boston. Those intended for work- 
room purposes have a broad base to steady 
their position on the table. Surmounting a 
wire gauze diaphragm, is a perforated cylin- 
der, with large openings near its top circum- 
ference for the promotion of air currents. 
These, by perfecting the combustion of the 
burning mixture of air and gas, not only in- 
crease its heating power, but prevent all 
smoke and odor. It is necessary to add that 
the meshes of the wire gauze should be kept 
clean by the occasional application of a tooth 
brush. 

Gas being in general use in the large cities 
and towns, an ample supply can always be 
obtained; but in the country and in thinly 
inhabited districts lamps must still be used- 
Lamps can be so constructed that they will 
produce a most intense heat by the use of 
alcohol, wood spirit, kerosene, camphene, 
and similar fluids, as fuel. Those hydro- 
carburets which have the lowest boiling point, 
and give the densest vapors, afford the great- 
est heat. Alcohol flame gives no smoke or 
unpleasant odor, the product of combustion 
being only carbonic acid and water, while 
lamp oil, especially where the supply of oil to 
the wick is insufficient, produces a black car- 
bonaceous deposit upon the bottom of the 
vessel, which occasions a loss of heat by radi- 



ation. Pyroxylic spirit is much less objec- 
tionable than lamp oil, and is said to be much 
cheaper than alcohol in heating capacity. 
The many other advantages of the latter, 
however, give it the preference over all other 
combustibles as a fuel for lamps. It should 
be about the specific gravity of 0.85 for this 
purpose. When a lamp is not in use the wick 
should always be covered with the extinguish- 
er to prevent loss by evaporation. 

The blow-pipe is an instrument that has 
been long used in the arts, and in mechani- 
cal pursuits, when small currents of intense 
heat are desired. The forms of the various 
blow-pipes in ordinary use must be familiar to 
all ; still there are points in their construc- 
tion to which we desire to direct special at- 
tention. They are generally made in the 
form of a tapering brass tube, and bent at the 
smallest end to a right angle, but without a 
sharp corner. Sometimes we find them 
made in the shape of a long cone, with the 
wide end stopped up, and a brass jefc with a 
small hole through it inserted in the side of 
the cone, near the wide end. This form has 
the advantage of collecting the moisture with 
which the air is charged as it comes from the 
mouth, and prevents the moisture from inter- 
fering with the flame that is being operated 
upon. Its weight is, however, a considerable 
drawback to its general use, especially in 
operations where both hands are required to 
be free in order to handle the work. 

There are many forms and methods of con- 
structing blow-pipes. Some of them have 
ingeniously ai'ranged stands to support them 
on the bench, thereby leaving the operator's 
hands at liberty ; and these stands are of 
much service in special operations. For all 
ordinary purposes, probably the first men- 
tioned blow-pipe, with a round ball added to 
it, and placed about the centre, in order to 
collect the moisture from the mouth, is as 
good as any. The ball ought to be hollow, and 
made so as it can be taken apart to allow the 
condensed moisture to escape when the ball 
becomes full. Some of the blow-pipes sold in 
the tool shops have, to all appearance, this ball 
placed on them merely as an ornament, for 
sometimes we find the tube to pass through 
the ball without any opening for the moisture 
to collect in it, and consequently, in cases of 



226 



AMERICAN HOROLOGICAL JOURNAL. 



this sort, the ball is useless. The metals 
blow-pipes are usually made of are very liable 
to become dirty through oxidation, and when 
placed between the lips are liable to impart a 
disagreeable taste. To avoid this, the top of 
the tube should . be supplied with a mouth- 
piece of ivory or other suitable material, 
shaped like the mouth-piece of a trumpet. 

This construction of the blow-pipe, for use 
at light work, has probably a combination of 
all the advantages that can be claimed for 
other forms. The moisture is collected and 
does not pass to the flame ; it is light, and, 
with the trumpet shaped mouth-piece, can be 
held easily in the mouth between the gums 
and the lips, without being in the least degree 
tiresome. Both hands are left at liberty to 
direct the work, while, by moving the head, 
the direction of the flame can be instantly 
changed, at a critical moment, which cannot 
always be done when a stand is used to sup- 
port the blow-pipe. 

In using the blow-pipe, the effect intended 
to be produced is an uninterupted, steady 
etream of air for some minutes together, if 
necessary, without an instant's cessation. 
Therefore the blowing can only be effected 
with the muscles of the cheeks, and not by 
the exertion of the lungs. It is only by this 
means that a steady, constant stream of air 
can be kept up, while the lungs will not be 
injured by the deprival of air. The details 
of the proper manner of using the blow-pipe 
are really more difficult to describe than to 
acquire by practice ; therefore the apprentice 
should apply himself at once to its practice, 
by which he will soon learn to produce a 
steady current of air. We would simply say 
that the tongue must be applied to the roof of 
the mouth, so as to interrupt the communica- 
tion between the passage of the nostrils and 
the mouth. The workman now fills his mouth 
with air, which is passed through the blow- 
pipe by compressing the muscles of the cheeks 
while he breathes through the nostrils, and 
uses the palate as a valve. "When the mouth 
becomes nearly empty, it is replenished by 
the lungs in an instant, while the tongue is 
momentarily withdrawn from the roof of the 
mouth. The stream of air can be continued 
for a long time without the least fatigue or 
injury to the lungs. The easiest way for the 



apprentice to accustom himself to the use of 
the blow-pipe, is first to learn to fill the mouth 
with air, and while the lips are kept firmly 
closed, to breath freely through the nostrils. 
Having effected this much, he may introduce 
the mouth-piece of the blow-pipe between his 
lips, and by inflating the cheeks, and breath- 
ing through the nostrils, he will soon learn to 
use the instrument without the least fatigue; 
the air being forced through the tube, against 
the flame, by the action of the muscles of the 
cheeks, while he continues to breath without 
interruption through the nostrils. Having 
become acquainted with this process, it only 
requires some practice to produce a steady 
jet of flame. A defect in the nature of the 
combustible used, as bad oil, bad alcohol, etc., 
or a dirty cotton wick in the lamp, or an un- 
trimmed one, will prevent a steady jet of 
flame. But frequently the fault lies in the 
small hole at the point of the blow-pipe being 
stopped by dirt or soot, and which prevents 
a steady stream of air, and leads to difficulty. 
Platinum pointed blow-pipes keep their 
shape better, and keep longer clean, than any 
other metal. 

Any flame of sufficient size can be used 
for blow-pipe operations, but in special cases, 
where smoke or other impurities would be 
likely to damage the work in progress, an 
alcohol lamp should be used ; but there 
must be no loose threads or dirt of any kind 
on the wick, or these will produce a smoky 
flame. The wick, likewise, should not be 
pulled up too high, as the same smoky flame 
would be produced. In situations where it 
is necessary to use a candle, it is well to cut 
the wick off short, and to bend it a little 
towards the article to which the heat is 
desired to be applied. But candles are not 
the best for blow-pipe operations, as the 
radiant heat reflected from the substance 
upon the wax or tallow will cause it to melt 
and run down the side of the candle; while, 
again, candles do not give heat enough. 

When a current of air is directed through 
a blow-pipe with a small straight aperture 
against a flame, it drives the latter before it 
in a long-pointed and conical projection. 
To produce a clean and uniform flame the 
tip end of the blow-pipe should barely pene- 
trate the flame, and, when it is desired to 



AMERICAN HOROLOGICAL JOURNAL. 



227 



give it volume, it must be slightly parted in 
the middle by drawing the tip of the blow- 
pipe across it. Iu this latter case, too, the 
blow-pipe should be directed at an angle of 
forty-five degrees across this channel. In 
blowing, the breath must be regulated, that 
the blast should neither be too strong nor 
too feeble ; for in the first instance the 
excessive air cools the flame, and in the 
latter the combustion is slow and imperfect. 
The long, narrow, blue flame which appears 
directly before the jet is the same as the blue 
part of the flame before the blow-pipe was 
applied to it, although changed in form, 
being now concentrated into a small cylin- 
drical space, whereas before it formed an 
envelope around the whole flame. Just 
before the point of this blue flame is the 
greatest heat, just as in a free flame, but 
with this difference — that in the latter case 
it formed a ring around the flame, while in 
the former it is concentrated into a focus. 
It is thus rendered sufficiently intense to 
fuse substances which were not sensibly 
acted on by the flame in its usual state. On 
this is founded the whole theory of the 
intense heat produced by the blow-pipe ; the 
effect which would otherwise be distributed 
over the whole surface of the flame is con- 
centrated into a small space, exactly as if 
the flame had been turned inside out. The 
surrounding illuminating portion of the flame 
prevents the heat from escaping. 

"When a flame is urged by the blow-pipe, 
the extreme heat is just at the tip of the 
outer white flame, where the combustion is 
most perfect, and where substances are 
rapidly burned or oxidized ; whilst the in- 
terior blue flame, in consequence of its excess 
of combustible matter, abstracts oxygen from, 
or reduces, substances ; so that several metals, 
when thus heated before the blow-pipe, are 
alternately oxidized and deoxidized by being 
placed in the outer and inner flame. For a 
practical illustration of oxidizing and deoxi- 
dizing, see page 219, VoL L of this Journal. 

In connection with the subject of the 
blow-pipe, a few remarks may be made as 
to the material that is the most suitable for 
holding or supporting the articles that are 
being operated upon. Pumice-stone is often 
used for this purpose, and it is very good, 



but probably charcoal is the best for all 
purposes. The value of charcoal as a mate- 
rial for placing small articles upon when 
under the influence of a flame from the 
blow-pipe, is as follows : It is infusible, and, 
being a poor conductor of heat, a substance 
can be exposed to a higher degree of heat 
upon it than upon any other substance. 
The best kind of charcoal is that of pine, 
linden, willow, alder, or any other soft wood. 
Coal from fir wood sparkles too freely, while 
that of the hard woods contains too much 
iron in its ashes. Smooth pieces, free from 
bark and knots, should be selected. It should 
be thoroughly burnt, and the annual rings 
or growths should be as close together as 
possible. If the charcoal is in masses, it 
should be sawed into pieces of convenient 
length, but so that the year growths run 
perpendicular to the broadest side, as the 
other sides, by their unequal structures, burn 
unevenly. 

Such is a review of the subject of heat. 
We have from time to time during the past 
eight months discussed the nature of heat, 
the laws of its transmission, and its effects 
upon different substances, and some of the 
methods by which it can be used in the 
mechanical arts to the best advantage. The 
writer was first induced to study the subject 
while working out the difficult problem of 
improving the compensation of pendulums. 
The effects afld consequences of heat are so 
visible all around us, and it is an agent that 
is required to be so universally used in our 
daily occupations — whether it be derived 
from combustion or chemical mixture, or 
any of the other sources — that a knowledge 
of the subject is of the utmost importance 
to all engaged in the mechanical arts. Let 
our young friends study the subject well. 
A clear comprehension of the laws of nature 
makes many operations beautifully plain 
which before appeared all mystery, and also 
tends to inspire within us greater reverence 
for the Great Architect of the Universe. 

_ Clyde. 

8@" Any of our friends that have a desire 
to see to how many useful purposes electro- 
plating with nickel may be applied, will te 
gratified with a visit to the establishment of 
L. L. Smith & Co., No. 6 Howard street, N.Y. 



228 



AMEBICAN HOBOLOGICAL JOUBNAL. 



THE PENDULUM 



.AS APPLIED TO THE 



MEASUREMENT OF TIME 



NUMBER TWO. 



TERRESTRIAL GRAVITY CONTINUED THEORY OF THE 

SIMPLE PENDULUM ILLUSTRATED TENDENCY TO 

DESCRIBE AN ELLIPSE FOUCAULT's EXPERI- 
MENT MATERIAL PENDULUM — CENTRE OF GRA- 
VITY CENTRE OF GYRATION — CENTRE OF 

OSCILLATION POINT OF SUSPENSION ANGULAR 

PENDULUM — CONICAL PENDULUM, ETC. 

In the last number we briefly investigated 
the laws that govern falling bodies, and ob- 
served that all bodies, irrespective of their 
size, when under the influence of gravity alone, 
fall with an equal velocity ; and that this 
velocity is continually accelerated until the 
body reaches its resting point. At the end 
of a second of time, after being liberated, the 
body attains a certain amount of speed, and 
gravity continuing to act upon ir, as much 
more velocity is imparted to it at the end of 
the next second, and as much a^ain during 
the third, and so on. We also noticed that 
bodies acquire the same velocity in rolling 
down the path of an inclined plane as they 
do in falling from the same elevation in a 
vertical line ; and also that the quickest way 
for a body to travel between two points is 
not always by following a straight line, but 
by following a cycloidal curve from the one 
point to the other. Gravity acte upon rising 
bodies in the same manner as it does on fall- 
ing bodies, but in a reversed order, thereby 
producing continually a retarding motion 
while the bodies are rising. Thus, a body 
projected perpendicularly into the air, if not 
influenced by the resistance of the air, would 
rise to a height exactly equal to that from 
which it must have fallen to acquire a final 
velocity the same as it had at the first instant 
of its ascent. 

On the foundation of these conclusions, 
which are to be found demonstrated mathe- 
matically in any text-book on natural philos- 
ophy, the whole theory of the oscillations of 
a simple pendulum will be explained by the 
following diagram. 

ABC is a horizontal line, and I B F is a 
cycloidal curve, the centre of which is the 
point J. The lines I J and F J are lines 



representing the evolute of the cycloid I B 
F. The point H represents the centre of 




oscillation of an imnginary pendulum. If 
this point be allowed to follow the inclined 
plane in the direction of B, the same kind of 
motion will be produced, and it will have ac- 
quired the tame velocity when it reaches B 
as it would if it fell in a vertical line from H 
to A ; and the velocity thus acquired will be 
sufficient power, were it not for the resistance 
of the air and friction, to cause it to ascend, 
in the same time, from B up to E, as it took 
to fall from H to B. The same result will 
ensue, but in different portions of time, if the 
point H be made to follow the lines I B or 
G B ; in both cases the point H will have 
acquired exactly the velocity on reaching B, 
to cause it to ascend on the opposite side to 
D or F in the same time as it took to descend 
from I or G to B. If this point, H, be at- 
tached to the thread K, and caused to follow 
the cycloidal curve I B F, it will reach B in 
the same time, from whatever point in the curve 
it may have started from ; and will also have 
obtained that velocity, on its descent, that is 
required to cause it to ascend the same dis- 
tance, in the same time, on the opposite side 
of B, and equal to that from which it fell. 

This explains the reason why the long and 
short vibrations of a simple pendulum are 
isochronal, or of equal duration, or performed 
in the same length of time ; or, in other 
words, the reason the pendulum always 
moves faster in proportion as its journey is 
longer, is, that in proportion as the arc de- 
scribed is more extended, the steeper are the 
declivities through which it falls, and the 
more its motion is accelerated. Thus, if a 
pendulum begins its downward motion at Ij 



AMERICAN HOROLOGICAL JOUENAL. 



229 



the accelerating force is twice as great as 
■when it is set free at H. The reason why 
long pendulums vibrate more slowly than 
shoi-t ones, is, that in corresponding arcs, or 
paths, the ball of the long pendulum has a 
greater journey to perform, without having a 
steeper line of descent. If we suppose three 
balls, or points, to be attached to three 
strings of the same length, it matters not 
how unequal the balls may be in weight, if 
we liberate them at the same time, one at I, 
one at H, and the other at G, they will arrive 
at B together, and each will have acquired a 
momentum which would be sufficient, were 
there no impediments to the motion, to carry 
it to a distance on the other side of B, cor- 
responding to the distance from which it fell. 
This is the reason why heavy and light pen- 
dulums vibrate in the same time if they be of 
the same length. 

It has been observed already, that in prac- 
tice a pendulum cannot be made to describe 
an exact cycloidal curve. In modern clock- 
work the maximum vibration of a pendulum 
need not be more than a degree and a half, 
or two degrees, on each side of the point of 
re-t ; and in that arc there is no difference 
between the cycloidal and circular curve that, 
in practice, makes itself visible by affecting 
the isochronal properties of a pendulum. 
Consequently, the pendulum may as well be 
allowed to swing in a circle as to endeavor to 
make it swing in a cycloid. If we take any 
fine clock, that is constructed on the common 
principle of maintaining the vibrations of the 
pendulum directly from the weight, and in- 
crease or diminish the weight, the length of 
the vibrations will be diminished or increased 
accordingly, and the rate of the clock will be 
affected according to the kind of escapement 
it may have. In the dead beat, or Graham 
escapement, any increase in the vibration of 
the pendulum has a tendency to make the 
clock go slow ; but this change of rate does 
not occur because the pendulum in not de- 
scribing a cycloid, but because it makes larger 
vibrations ; the pallets have a corresponding 
increase of friction, by having to travel farther 
on the teeth of the scape-wheel, and hence 
the vibrations of the pendulum are slower. 
If the error in the rate of the clock had its 
origin in the pendulum describing a circular 



curve i